NEW312463
REGRESSION (Safari 26.4): navigator.userActivation.isActive is false, breaking fullscreen on YouTube and others 
https://bugs.webkit.org/show_bug.cgi?id=312463
Summary REGRESSION (Safari 26.4): navigator.userActivation.isActive is false, breakin...
jimmy
Reported 2026-04-16 04:47:48 PDT
Created attachment 479102 [details] dev tools output immediately inside trusted click handlers, breaking requestFullscreen on YouTube, Patreon, and other video sites Steps: Go to youtube.com, click the fullscreen icon on any video. Nothing happens. Pressing F works correctly. Diagnostic: Inside an isTrusted: true click handler on a button, navigator.userActivation.isActive returns false, causing video.requestFullscreen() to silently reject. hasBeenActive returns true, so the user has clicked — only the transient activation on this specific click is missing. Regression: Worked in Safari 26.3. Broke in Safari 26.4.
Attachments
dev tools output (76.27 KB, image/png)
2026-04-16 04:47 PDT, jimmy 		no flags
Details
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Alexey Proskuryakov
Comment 1 2026-04-16 13:12:26 PDT
Thank you for the report! I cannot reproduce this with Safari 26.5 beta, and I don't think that we've had other reports of the fullscreen button being broken on Youtube. Could there be anything unusual about your configuration, such as perhaps any extensions?
Radar WebKit Bug Importer
Comment 2 2026-04-23 04:48:13 PDT
<rdar://problem/175418432>
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