The JavaScript function createIndicatorForStickyElements which is used by position: sticky tests measures the size of a div to make an idicator div. The size of the divs that it measures sometimes use web fonts though, so it's possible for the indicator div to be the wrong size if the function executes before web fonts have loaded.
Created attachment 436612 [details] Patch
This patch modifies the imported WPT tests. Please ensure that any changes on the tests (not coming from a WPT import) are exported to WPT. Please see https://trac.webkit.org/wiki/WPTExportProcess
Created attachment 436613 [details] Patch
Created attachment 436614 [details] Patch
Submitted web-platform-tests pull request: https://github.com/web-platform-tests/wpt/pull/30211
Comment on attachment 436614 [details] Patch Thanks for the review!
Committed r281698 (241048@main): <https://commits.webkit.org/241048@main> All reviewed patches have been landed. Closing bug and clearing flags on attachment 436614 [details].
<rdar://problem/82442988>