301484 2025-10-26 07:42:33 -0700 Video playback fails on PWA after reopening stuck on first frame 2025-10-27 08:56:00 -0700 1 1 1 Unclassified WebKit New Bugs WebKit Nightly Build iPhone / iPad iOS 26 RESOLVED DUPLICATE 300990 P2 Major --- 1 ziyak97 webkit-unassigned oldest_to_newest 2154330 0 ziyak97 2025-10-26 07:42:33 -0700 Title iOS: Videos in Home-Screen web apps (PWAs) show poster/first frame but don’t advance; play() resolves, frames don’t decode Summary When websites are added to the Home Screen and launched as standalone web apps, HTML5 video often gets stuck on the poster/first frame. HTMLMediaElement.play() resolves and media events fire (loadeddata → canplay → playing), but playback does not advance. This occurs across multiple, unrelated sites, including **YouTube** installed to the Home Screen and custom apps (e.g., Cloudinary MP4/HLS), indicating a system-wide iOS/WebKit issue in PWA context. Steps to Reproduce 1) In Safari, open https://youtube.com. 2) Share → Add to Home Screen. 3) Launch the YouTube icon (standalone PWA). 4) Start any video (autoplay or manual play). 5) Observe: Events fire; but the poster/first frame remains and the picture does not update. Expected Video frames decode and advance; poster is replaced by video frames. Actual - play() promise resolves; loadeddata/canplay/playing fire. - currentTime remains 0. - No new frames decode: getVideoPlaybackQuality().totalVideoFrames stays constant (delta = 0). Diagnostics (from Web Inspector on device) - Event log shows playing without visual motion. - Playback quality sampled at 500 ms intervals shows delta = 0 while paused = false. Workarounds Tried - Remove poster + tiny seek (currentTime += 0.01) after loadeddata → does not work. Impact Affects video playback across any Home-Screen web app, including major sites (YouTube) and enterprise PWAs; severe impact on media use-cases. 2154451 1 gsnedders 2025-10-27 08:53:58 -0700 *** Bug 301485 has been marked as a duplicate of this bug. *** 2154452 2 ap 2025-10-27 08:56:00 -0700 *** This bug has been marked as a duplicate of bug 300990 ***