We are running into this same issue in 5.5.3. Absolutely killing us! You can seem to hold it at bay so long as you have the camera hidden and do not try to directly manipulate the camera via the normal selection handles. I.e. Key a parameter and do you adjustments there. Not ideal.
I have also seen the issue where objects pop to an incorrect position and snap into place if you move a frame. This could also all be related to an issue where, using procedurally created control rigs, we get duplicate joint controllers and they continue to replicate with every save. Sequencer is doing something it didn’t do before. Seems to have been this way since at least 5.3. (Popping objects at least.)