@font-face CSS not loading in page editor. wp-edit-post-js-after

[djcowan]

Description

@font-face CSS not loading in page editor when in desktop preview for existing websites.

• Fonts visible wjhen switching to mobile, tablet preview
• wp-edit-post-js-after styles contain reference in __unstableResolvedAssets
• Noted on existing gutenberg enabled websites (mu and single)
• Iframe does not appear to load for desktop preview
• Disabling gutenberg plugin fixes issue
• changing text element font style in preview mode creates error

Step-by-step reproduction instructions

Not reproduceable - effects existing websites

Screenshots, screen recording, code snippet

GIST contining wp-edit-post-js-after data: https://gist.github.com/djcowan/55252ddedaa412512c15535f8e6af36e

Environment info

• Version 15.8.1 | By Gutenberg Editor Team
• Wordpress Version 6.2.2
  Is this site using HTTPS?
  Yes
  Is this a multisite?
  Yes

Please confirm that you have searched existing issues in the repo.

Yes

Please confirm that you have tested with all plugins deactivated except Gutenberg.

No

[mrfoxtalbot]

Thank you for reporting this @djcowan.

Disabling gutenberg plugin fixes issue

Flagging this for you, @getdave. This might be a regression.

[djcowan]

FYI only 15.9.1 release didn't correct the issue within the page/post editor desktop view

[getdave]

Hopefully this can be triaged soon. I will try to get around to testing but if Core Editor folks get here first that would be great.

[djcowan]

Additional feedback:
wp-fonts-local does not populate as per instructions found here:
[Webfonts] Rename to Fonts API #46749

Testing Instructions:

- item 4:

Examine the dynamically generated @font-face stylings in the admin area by:
Open Dev Tools in your favorite browser
Search for wp-fonts-local (which is in the )

[djcowan]

Updating with additional additional feedback - hoping to limit uneccessary checks by the core and gutenberg teams
With reference to - Iframe enqueuing: Add editorStyle and warning. (#50091)

Gutenberg 16.0.0 has effected the page editor iframe render although the effect is currently localised to one (1) site.
-wp-fonts-local appearing as expected

• iframes enqueue warnings are visible ❤️

Other sites are not yet reflecting the changes by 16.0.0 release
i.e iframe warnings are not visible

We are checking that:
Gutenberg plugin is installed and at 16.0.0 with experiment options disabled

• Health check, performance plugin results
  flushing all caches
  template and pattern includes
  and anything else we think might be effecting output

• very happy with the recent changes and fully understand if this issue is stashed as unable to reproduce

[djcowan]

Closing this issue – issue identified as being related to wpmudev smart crawl pro