Editor / Safari / Atomic: Metabox panels floating over editor content area

[JoshuaGoode]

This is a WordPress.com / Automattic duplicate issue for internal tracking and triaging. I've opened an issue with Gutenberg at WordPress/gutenberg#33668

Description

As of Gutenberg 10.7.0, and now WordPress core 5.8, metabox panels are no longer restricted to their editor region and are floating over the editor content area in Safari.

It seems display changes to .edit-post-visual-editor might be related. Possibly from #32581

Steps to reproduce the behavior

1. Create a post/page with multiple paragraphs worth of content.
2. Enable the Custom fields panel within editor Preferences. Or, install a plugin such as Yoast which automatically adds and enables an editor metabox panel.

What I expected to happen

Metabox panels are restricted to the bottom of the editor, below body content.

What actually happened

Metabox panels are floating over editor body content.

Context

Browser / OS version

Safari, tested as recent as 14.1 and as far back as 12.1

Does this happen on simple or atomic sites or both?

Atomic

Level of impact (Does it block purchases? Does it affect more than just one site?)

Safari users, mostly those with Yoast installed or those with other plugins that add metabox panels and enable them by default.

Workaround

One workaround, for now, is to hide the panels.

1. Access your editor preferences while in the editor by clicking ⋮ > Preferences
2. Disable the additional panels within the Panels area.

[formosattic]

+1 4166973-zd-woothemes

[mrfoxtalbot]

Awesome report @JoshuaGoode. I have added the "Core Fix Needed" tag. Thank you!

[jp-imagines]

Looks like there was a report of this in 4177745-zen. Not sure of the user's browser, though.

[jasmussen]

For those of you able to reproduce this (from what I can tell this is a Safari 13 and older issue), I believe I have a fix in WordPress/gutenberg#33817. It should be testable using http://gutenberg.run/33817.

[jordesign]

WordPress/gutenberg#33668 is closed now - and I can no-longer recreate this issue. Closing issue.