Adjusting motion effects on flattened clip while in multicam preview mode causes playback issue

Issue: Using motion effects on flattened multiclips while the program monitor is still in multicam mode results in losing the ability to play video. This comes up regularly when working with a multiclip in which a 4k clip is mixed with HD footage, which one might want to resize and reposition.

Steps: 
- edit in multicam mode, with the multicam preview monitor active in the program window
- flatten a clip on the timeline for the purpose of punching in on the 4k shot
- while the multicam preview mode is still active, adjust the clip in the effect controls panel (scale, rotation, position)
- try to keep working

Actual: clip is resized, but playback controls don't work anymore. Not space or JKL or on-screen buttons. Restarting clears the issue and the motion effects remain applied. This is true whether the flattened clip is the only piece of video on any track, or if the clip is a dupe of the original multicam on the layer above. 

note: simply resizing or rotating an _unflattened_ clip causes a brief hang of 20-30 seconds after which playback control resumes. It's possible that waiting long enough would clear the above issue, but not in 5 minutes or less. 

Workaround: disengaging multicam preview mode, then making motion effect adjustments, then re-engaging multicam mode works, it's just a bothersome amount of additional steps. 

Premiere: v 26.2.0 build 65
OS: MacOS Sequoia 15.7.5