Flex pitch havoc, destroying my track

OK, as it turns out Flex Pitch was not itself the root of the problem, but it revealed another problem to me. What was happening was I had at some time cut some regions to make some edits. However, it seems that somehow, other new regions, along with a slew of very short, self, created, millisecond long cuts began appearing over the top of the original track. Or at least the sound of the original track. There were no actual visible tracks underneath when I dragged a region away. Over the top of my edited parts.

It's as if the edits truncated the rest of the region and these after the very short cuts between them and new duplicated regions appeared. Background noise in the original tracks was noticeable, so there are other regions without singing, perhaps including some very short cuts, where I mute the track to eliminate the noise. But the very short bits were muted so I assume they were also problematic.

Where they overlapped with the newly duplicated track and some "invisible" audio parts of the original track, was what was creating these short bursts of duplicated tracks. Imposing themselves over some version of the original unedited track, somehow still playing underneath, as sound bursts. The solution turns out to be where these were happened is to delete all the edited cut parts and the very short cuts between them and deleting them. And then dragging the original tracks out where then entire performance remained intact, over to another regions where this was no longer happening.

And still needing to go in and doing some other edits, like pitch fixes, all over again as the original parts remained unedited.

What the **** happened here? Why was Logic doing this? A cut region shouldn't be creating duplicates unless I have something set wrong to make it happen. Or was there is some kind of glitch? 'm finding the same thing on at least one other backing vocal track as well. What causes this, and how can I prevent it happening in the future?