Unsupported Block: Visual glitch when zooming in/out the content (iOS only)

[fluiddot]

Description

When doing the TC001 test case of Unsupported Block Editing on WordPress iOS, I noticed that zooming in/out the unsupported block editor content produces a visual glitch (see attached video capture).

NOTE: This is not a regression because I managed to reproduce it on version 17.5 of the main apps.

Step-by-step reproduction instructions

Precondition:
A WP.com Simple site (it can be reproduced on an Atomic site too).

1. On the site described above, add a post, then add a block that's not yet supported on mobile
2. Log into the WordPress iOS mobile app using the site's WP.com account
3. Open the post and expect to see the block rendered as a placeholder with the text "Unsupported"
4. Tap the (?) icon and expect the option to edit the block in a web browser to be shown
5. Tap the edit in a web browser button and expect the block to be shown, ready to edit, on a new screen
6. Pinch the content to zoom in and out
7. Observe the visual glitch (as shown in the attached video capture)

Expected behaviour

Zooming in/out the content shouldn't produce any visual glitches.

Actual behaviour

Zooming in/out the content produces a visual glitch.

Screenshots or screen recording (optional)

ube-zoom-glitch.mp4

WordPress information

• WordPress version: N/A
• Gutenberg version: v10.8.2-with-min-js-assets
• Are all plugins except Gutenberg deactivated? N/A
• Are you using a default theme (e.g. Twenty Twenty-One)? N/A

Device information

• Device: iPhone 11
• Operating system: iOS 14.2
• WordPress app version: 432a8eceb5140e664fcb7e48db234193748d9f1b