Subtitles and rewind/fast-forward not following Picture-in-Picture mode for Disney+

I've been having an issue with picture-in-picture (PiP) mode where the subtitles and rewind/fast-forward buttons (rr/ff) won't follow the video into the small player for Disney+ specifically. I have no issues with YouTube or any other site. The subtitles and rr/ff just stay with the original video player on the site while the video is in PiP mode. I can see the subtitle button on the PiP player, but it is grayed out and I can't click it. I've updated both Firefox and my computer (Windows 11) and reinstalled Firefox, cleared cookies and cache, and still no dice. Any advice? Thanks!

(In the screenshot, the PiP player isn't showing video, but I think that's just because of Disney's anti-piracy software - I can see the video in the PiP player on my screen.)