Moving/scaling clips is broken in Beta - upon playback, layers move to a random place/scale

I have a timeline (1080x1920 25fps) with 3 layers of video (one of which is a Lumetri adjustment layer) and, seemingly importantly, 3 tracks of subtitles. In PPro Beta (25.2.0x127), if I reposition/rescale one of the layers, when I start play back (or scrub), it jumps to a random position and scale. When I stop playback, it snaps back to its previous position. This does not happen in the release version 25.1.0 (Build 73). This renders the Beta version unusable for my current project.

If I render the sequence, the problem goes away - ie. the actual rendered video is fine - UNTIL a subtitle appears on screen (even if just 1 subtitle track is active), and then one of the video layers jumps to a random position and scale. If I turn off all subtitles, the problem goes away. As far as I can tell.