Notes gone missing in region overlaps (Logic 10.5.1)

I get a situation where notes are missing at the borders of regions where two regions have overlapped, having to fetch the lost content from the backups, and it's not a display problem. And although I'm 1000% sure I'm in "overlap mode" (I almost never change it), this has happened a great number of times, so it can't be a pilot error.

 

Sometimes I've noticed (by ear) it happening while working on my regions, and although I instantly caught it happening, the notes cannot be restored with undo steps, but I only get them back by not saving, and reloading my save.

 

The only way to avoid the error seems to be avoid overlaps or join all regions, which a bummer, because the music within my synth track is extremely busy and complex, I have a better sense of my project when different sections of the music are kept in separate regions.

 

I wonder if it has to do with the Replace mode?

I wonder if it has to do with the Replace mode?

 

I think not. I never use it, and believe I would have noticed the distinctive orange color if it was ever turned on, I've very rarely recorded into the affected locations (I've only recorded somewhere in the middle of the affected regions), and I wasn't able to reproduce this problem using replace mode. I also asked myself if it's the R-button being deployed while recording to other regions, but deploying the R-button doesn't seem to wipe out anything.

If it's not a software glitch, then should one infer a corrupt project file? Logic Pro keeps doing this every day, and this time I've made sure Replace Mode (orange) is turned off. The "Overlap" setting has been enabled at all times.

The unknown variable in your screenshot with description of the actions that led to this result is what "messing around" exactly was done with the region borders?

The unknown variable in your screenshot with description of the actions that led to this result is what "messing around" exactly was done with the region borders?

 

"Messing around" - meaning (sligtly) dragging them in or out (ie. contracting/extending), and nothing else. But I doubt this is the cause, since the notes within the overlapped borders seem to have disappeared on a daily basis, and I don't believe I've had need to change (by dragging) the borders that often. The data on this virtual instrument track was originally subdivided into ~10 concatenated regions, with some small overlaps in most of them. Over a few weeks, I've had to fetch the notes from backup files for successively each of these overlapped regions, as the notes within the region overlaps have one-by-one disappeared while saving and loading. (This has happened to other tracks, as well, but we won't bother with that since they contain a minuscule part of the actual composition.)