Random Brightness Flicker in Slow Motion (Machine Learning) Clips After Export

In slow motion clips (using machine learning), a frame occasionally flashes — as if the brightness suddenly increases or decreases. This happens randomly in some clips with slow mo (machine learning), but only after exporting.

The same projects had been exported previously in the earlier version of Final Cut without this issue, so the problem appears to have started with the current version 11.2.

[Edited by Moderator]