diff --git a/packages/block-editor/src/components/block-list/insertion-point.js b/packages/block-editor/src/components/block-list/insertion-point.js
index c7eb0e8d6ee80a..8055dff0e37e43 100644
--- a/packages/block-editor/src/components/block-list/insertion-point.js
+++ b/packages/block-editor/src/components/block-list/insertion-point.js
@@ -51,9 +51,10 @@ function InsertionPointInserter( {
 			return;
 		}
 
+		const { ownerDocument } = ref.current;
 		const targetRect = target.getBoundingClientRect();
 		const isReverse = clientY < targetRect.top + targetRect.height / 2;
-		const blockNode = getBlockDOMNode( clientId );
+		const blockNode = getBlockDOMNode( clientId, ownerDocument );
 		const container = isReverse ? containerRef.current : blockNode;
 		const closest =
 			getClosestTabbable( blockNode, true, container ) || blockNode;
@@ -100,7 +101,8 @@ function InsertionPointPopover( {
 	containerRef,
 	showInsertionPoint,
 } ) {
-	const element = getBlockDOMNode( clientId );
+	const { ownerDocument } = containerRef.current;
+	const element = getBlockDOMNode( clientId, ownerDocument );
 
 	return (
 		<Popover
diff --git a/packages/block-editor/src/components/block-list/use-multi-selection.js b/packages/block-editor/src/components/block-list/use-multi-selection.js
index 696ed2f55c5396..c3a4821d4050ac 100644
--- a/packages/block-editor/src/components/block-list/use-multi-selection.js
+++ b/packages/block-editor/src/components/block-list/use-multi-selection.js
@@ -102,7 +102,10 @@ export default function useMultiSelection( ref ) {
 			const selection = defaultView.getSelection();
 
 			if ( selection.rangeCount && ! selection.isCollapsed ) {
-				const blockNode = getBlockDOMNode( selectedBlockClientId );
+				const blockNode = getBlockDOMNode(
+					selectedBlockClientId,
+					ownerDocument
+				);
 				const { startContainer, endContainer } = selection.getRangeAt(
 					0
 				);
@@ -129,8 +132,8 @@ export default function useMultiSelection( ref ) {
 		const start = multiSelectedBlockClientIds[ 0 ];
 		const end = multiSelectedBlockClientIds[ length - 1 ];
 
-		let startNode = getBlockDOMNode( start );
-		let endNode = getBlockDOMNode( end );
+		let startNode = getBlockDOMNode( start, ownerDocument );
+		let endNode = getBlockDOMNode( end, ownerDocument );
 
 		const selection = defaultView.getSelection();
 		const range = ownerDocument.createRange();
diff --git a/packages/block-editor/src/components/writing-flow/focus-capture.js b/packages/block-editor/src/components/writing-flow/focus-capture.js
index 8440a3097e0428..15bdb63d441d9c 100644
--- a/packages/block-editor/src/components/writing-flow/focus-capture.js
+++ b/packages/block-editor/src/components/writing-flow/focus-capture.js
@@ -80,7 +80,10 @@ const FocusCapture = forwardRef(
 
 			// If there is a selected block, move focus to the first or last
 			// tabbable element depending on the direction.
-			const wrapper = getBlockDOMNode( selectedClientId );
+			const wrapper = getBlockDOMNode(
+				selectedClientId,
+				ref.current.ownerDocument
+			);
 
 			if ( isReverse ) {
 				const tabbables = focus.tabbable.find( wrapper );
diff --git a/packages/block-editor/src/components/writing-flow/index.js b/packages/block-editor/src/components/writing-flow/index.js
index f761e14eee0821..a833661775236c 100644
--- a/packages/block-editor/src/components/writing-flow/index.js
+++ b/packages/block-editor/src/components/writing-flow/index.js
@@ -305,12 +305,14 @@ export default function WritingFlow( { children } ) {
 	function onMouseDown( event ) {
 		verticalRect.current = null;
 
+		const { ownerDocument } = event.target;
+
 		// Clicking inside a selected block should exit navigation mode and block moving mode.
 		if (
 			isNavigationMode &&
 			selectedBlockClientId &&
 			isInsideRootBlock(
-				getBlockDOMNode( selectedBlockClientId ),
+				getBlockDOMNode( selectedBlockClientId, ownerDocument ),
 				event.target
 			)
 		) {
@@ -417,6 +419,8 @@ export default function WritingFlow( { children } ) {
 		const hasModifier =
 			isShift || event.ctrlKey || event.altKey || event.metaKey;
 		const isNavEdge = isVertical ? isVerticalEdge : isHorizontalEdge;
+		const { ownerDocument } = container.current;
+		const { defaultView } = ownerDocument;
 
 		// In navigation mode, tab and arrows navigate from block to block.
 		if ( isNavigationMode ) {
@@ -489,11 +493,22 @@ export default function WritingFlow( { children } ) {
 					event.preventDefault();
 					selectBlock( focusedBlockUid );
 				} else if ( isTab && selectedBlockClientId ) {
-					const wrapper = getBlockDOMNode( selectedBlockClientId );
+					const wrapper = getBlockDOMNode(
+						selectedBlockClientId,
+						ownerDocument
+					);
 					let nextTabbable;
 
 					if ( navigateDown ) {
 						nextTabbable = focus.tabbable.findNext( wrapper );
+
+						if ( ! nextTabbable ) {
+							nextTabbable =
+								ownerDocument.defaultView.frameElement;
+							nextTabbable = focus.tabbable.findNext(
+								nextTabbable
+							);
+						}
 					} else {
 						nextTabbable = focus.tabbable.findPrevious( wrapper );
 					}
@@ -517,7 +532,10 @@ export default function WritingFlow( { children } ) {
 		// Navigation mode (press Esc), to navigate through blocks.
 		if ( selectedBlockClientId ) {
 			if ( isTab ) {
-				const wrapper = getBlockDOMNode( selectedBlockClientId );
+				const wrapper = getBlockDOMNode(
+					selectedBlockClientId,
+					ownerDocument
+				);
 
 				if ( isShift ) {
 					if ( target === wrapper ) {
@@ -559,9 +577,6 @@ export default function WritingFlow( { children } ) {
 			return;
 		}
 
-		const { ownerDocument } = container.current;
-		const { defaultView } = ownerDocument;
-
 		// When presing any key other than up or down, the initial vertical
 		// position must ALWAYS be reset. The vertical position is saved so it
 		// can be restored as well as possible on sebsequent vertical arrow key
diff --git a/packages/block-editor/src/utils/dom.js b/packages/block-editor/src/utils/dom.js
index 89eec45cca5a5b..96a8a9e60c53bd 100644
--- a/packages/block-editor/src/utils/dom.js
+++ b/packages/block-editor/src/utils/dom.js
@@ -3,24 +3,26 @@
  * if exists. As much as possible, this helper should be avoided, and used only
  * in cases where isolated behaviors need remote access to a block node.
  *
- * @param {string} clientId Block client ID.
+ * @param {string}   clientId Block client ID.
+ * @param {Document} doc      Document to search.
  *
  * @return {Element?} Block DOM node.
  */
-export function getBlockDOMNode( clientId ) {
-	return document.getElementById( 'block-' + clientId );
+export function getBlockDOMNode( clientId, doc = document ) {
+	return doc.getElementById( 'block-' + clientId );
 }
 
 /**
  * Returns the preview container DOM node for a given block client ID, or
  * undefined if the container cannot be determined.
  *
- * @param {string} clientId Block client ID.
+ * @param {string}   clientId Block client ID.
+ * @param {Document} doc      Document to search.
  *
  * @return {Node|undefined} Preview container DOM node.
  */
-export function getBlockPreviewContainerDOMNode( clientId ) {
-	const domNode = getBlockDOMNode( clientId );
+export function getBlockPreviewContainerDOMNode( clientId, doc ) {
+	const domNode = getBlockDOMNode( clientId, doc );
 
 	if ( ! domNode ) {
 		return;
diff --git a/packages/components/src/autocomplete/index.js b/packages/components/src/autocomplete/index.js
index 38a5a0d58fd6bb..08815f4fff9ad4 100644
--- a/packages/components/src/autocomplete/index.js
+++ b/packages/components/src/autocomplete/index.js
@@ -136,8 +136,18 @@ function filterOptions( search, options = [], maxResults = 10 ) {
 	return filtered;
 }
 
+function getActiveWindow( doc ) {
+	const { activeElement } = doc;
+
+	if ( activeElement.nodeName === 'IFRAME' ) {
+		return getActiveWindow( activeElement.contentDocument );
+	}
+
+	return doc.defaultView;
+}
+
 function getRange() {
-	const selection = window.getSelection();
+	const selection = getActiveWindow( document ).getSelection();
 	return selection.rangeCount ? selection.getRangeAt( 0 ) : null;
 }
 
diff --git a/packages/components/src/sandbox/index.js b/packages/components/src/sandbox/index.js
index dd779b984c28ad..c7b6543d74426d 100644
--- a/packages/components/src/sandbox/index.js
+++ b/packages/components/src/sandbox/index.js
@@ -2,7 +2,6 @@
  * WordPress dependencies
  */
 import { Component, renderToString, createRef } from '@wordpress/element';
-import { withGlobalEvents } from '@wordpress/compose';
 
 /**
  * Internal dependencies
@@ -38,6 +37,9 @@ class Sandbox extends Component {
 			this.trySandboxWithoutRerender,
 			false
 		);
+		const { ownerDocument } = this.iframe.current;
+		const { defaultView } = ownerDocument;
+		defaultView.addEventListener( 'message', this.checkMessageForResize );
 	}
 
 	componentDidUpdate( prevProps ) {
@@ -51,6 +53,12 @@ class Sandbox extends Component {
 			'load',
 			this.trySandboxWithoutRerender
 		);
+		const { ownerDocument } = this.iframe.current;
+		const { defaultView } = ownerDocument;
+		defaultView.removeEventListener(
+			'message',
+			this.checkMessageForResize
+		);
 	}
 
 	isFrameAccessible() {
@@ -73,7 +81,7 @@ class Sandbox extends Component {
 		}
 
 		// Verify that the mounted element is the source of the message
-		if ( ! iframe || iframe.contentWindow !== event.source ) {
+		if ( ! iframe || iframe !== event.source.frameElement ) {
 			return;
 		}
 
@@ -260,8 +268,4 @@ class Sandbox extends Component {
 	}
 }
 
-Sandbox = withGlobalEvents( {
-	message: 'checkMessageForResize',
-} )( Sandbox );
-
 export default Sandbox;
diff --git a/packages/format-library/src/link/index.js b/packages/format-library/src/link/index.js
index 6f56f9161410b7..28daefc0c68886 100644
--- a/packages/format-library/src/link/index.js
+++ b/packages/format-library/src/link/index.js
@@ -116,6 +116,7 @@ export const link = {
 					activeAttributes,
 					value,
 					onChange,
+					forwardedRef,
 				} = this.props;
 
 				return (
@@ -160,6 +161,7 @@ export const link = {
 								activeAttributes={ activeAttributes }
 								value={ value }
 								onChange={ onChange }
+								forwardedRef={ forwardedRef }
 							/>
 						) }
 					</>
diff --git a/packages/format-library/src/link/inline.js b/packages/format-library/src/link/inline.js
index 9d190ac201c775..9107bfa6bd916a 100644
--- a/packages/format-library/src/link/inline.js
+++ b/packages/format-library/src/link/inline.js
@@ -26,6 +26,7 @@ function InlineLinkUI( {
 	onChange,
 	speak,
 	stopAddingLink,
+	forwardedRef,
 } ) {
 	/**
 	 * A unique key is generated when switching between editing and not editing
@@ -54,7 +55,9 @@ function InlineLinkUI( {
 	const [ nextLinkValue, setNextLinkValue ] = useState();
 
 	const anchorRef = useMemo( () => {
-		const selection = window.getSelection();
+		const { ownerDocument } = forwardedRef.current;
+		const { defaultView } = ownerDocument;
+		const selection = defaultView.getSelection();
 
 		if ( ! selection.rangeCount ) {
 			return;
diff --git a/packages/rich-text/src/component/format-edit.js b/packages/rich-text/src/component/format-edit.js
index 753e6a02739b57..2f320d68dee4d8 100644
--- a/packages/rich-text/src/component/format-edit.js
+++ b/packages/rich-text/src/component/format-edit.js
@@ -30,6 +30,7 @@ export default function FormatEdit( {
 	value,
 	allowedFormats,
 	withoutInteractiveFormatting,
+	forwardedRef,
 } ) {
 	return formatTypes.map( ( { name, edit: Edit, tagName } ) => {
 		if ( ! Edit ) {
@@ -67,6 +68,7 @@ export default function FormatEdit( {
 				value={ value }
 				onChange={ onChange }
 				onFocus={ onFocus }
+				forwardedRef={ forwardedRef }
 			/>
 		);
 	} );
diff --git a/packages/rich-text/src/component/index.js b/packages/rich-text/src/component/index.js
index 04fcb77f92b606..7827dfd2b49e3f 100644
--- a/packages/rich-text/src/component/index.js
+++ b/packages/rich-text/src/component/index.js
@@ -1138,6 +1138,7 @@ function RichText(
 					onChange={ handleChange }
 					onFocus={ focus }
 					formatTypes={ formatTypes }
+					forwardedRef={ ref }
 				/>
 			) }
 			{ children &&