Email Designer: body content inside three nested sections does not render in iOS Apple Mail (table nesting depth)

[austinspooner]

Description

Content placed inside three nested full-width sections in the Email Designer is
dropped entirely by Apple Mail on iOS. The delivered HTML is structurally intact
(tables balanced, 65 open / 65 close) and renders completely in a browser, in
macOS Apple Mail, and in the Gmail iOS app. Only iOS Apple Mail drops it.

Actual Behavior

On iOS Apple Mail the template header and footer render normally and the middle
content area is blank white. Preview text confirms the copy is present in the
payload. The same message renders correctly in macOS Apple Mail, the Gmail iOS
app, and desktop browsers.

Measuring table nesting depth for every element containing visible text in the
delivered message shows a clean cut:

Content	Table nesting depth	Renders on iOS Apple Mail
Footer address block	11	Yes
Footer logo	11	Yes
Header date line	14	Yes
Control content (single section)	14	Yes
Body copy inside 3 nested sections	28	No
Heading inside 3 nested sections	28	No

Everything at 14 renders, everything at 28 is dropped. I have not bisected the
intermediate depths, so the actual threshold is somewhere between 14 and 28.
Maximum element nesting depth in the failing document is 122.

Expected Behavior

Content renders in iOS Apple Mail regardless of how sections are nested. Nothing
in the UI currently signals that a section inside a section inside a section is
not possible, and the designer allows it.

Steps to Reproduce

1. Create a new Email Designer communication on the stock template.
2. Add a full-width section. Inside it, add a second section. Inside that, a
   third. Single column each, no styling changes.
3. Put a heading and a paragraph of filler text in the innermost section.
4. Leave the template header and footer as-is.
5. Send to an address you read in Apple Mail on an iPhone.

Issue Confirmation

• Perform a search on the Github Issues to see if your bug is already reported.
• Reproduced the problem on a fresh install or on the demo site.

Rock Version

19

Client Culture Setting

en-us