Picture-in-Picture seek controls bypass MediaSession ad restrictions on YouTube
In Microsoft Edge, the Picture-in-Picture overlay exposes functional +10s/-10s seek controls during YouTube ad playback. The seek action advances the ad playhead even when YouTube has declared the seekforward action as unavailable via the Media Session API. Repro: InPrivate window, logged out of YouTube Play any video on youtube.com When pre-roll ad starts, click the in-player PiP icon Press +10s seek-forward on the PiP overlay Observed: a non-skippable NPCI ad followed by a Maggi ad were both bypassed in ~10 seconds of wall-clock time. The main <video> element briefly buffers during seek, consistent with HTMLMediaElement.currentTime being mutated directly rather than dispatched through the page's registered MediaSession action handlers. Cross-browser: verified the same flow in Google Chrome on the same Windows install. Seek-forward during ad playback does NOT advance the playhead, confirming YouTube's MediaSession setup is correct and isolating the issue to Edge's PiP implementation. Impact: affects any site using the Media Session API to restrict seek — live streams, DRM-protected content, ad-bound playback. Not YouTube-specific. Environment: Edge version: latest stable channel OS: Windows 11 - Chrome compared: latest stable channel