Row item justification not displaying properly in Editor

[lemswisc]

Describe the bug
If you put Blocks in a Row with a centered Justification, the items are not centered in the editor.

To Reproduce
I think the easiest way to demonstrate is to show an existing pattern that looks wildly different on the front and back end.
https://wordpress.org/patterns/pattern/new-cta-section/
Copy the pattern into the Pattern editor for the Pattern Directory.
Notice how the buttons are not centered in the Editor.

Expected behavior
The Buttons should be centered in the editor.

Screenshots
Pattern in the editor:

Pattern on the directory:

Desktop (please complete the following information):
Windows 10, Chrome

Additional context
There seem to be bigger issues with Rows/Stacks, but this was the easiest to demonstrate. If you simply fixed-width items in a Group, then toggle between a row and a stack, nothing happens there at all (when they should switch from next to each other and on top of each other). I think the editor CSS around Groups likely needs some updates.