I tried to grab a region on timeline to another place, normally it moves. This time it didn't move, but divided to one or more regions. I don't remember, did it divide as half of first or to the same size. As I couldn't move the regions, I shut gb and next time the moving was OK again. Why they procreated, what I did for that and for what this procreating is good? For chorus? It happened a year ago and I was grabbing the regions the same way as I used to move them. At least I understood so. But there have to be some kind of difference. Have no video as then I didn't came for that.

AFAIK the only way GB offers to cut/split Regions is Command-T [split @ playhead], maybe you unintentionally invoked that command..? Otherwise I suppose it could have just been a glitch -- if closing/opening GB [or doing a shutdown/restart] fixes an unusual/unexpected issue, often it means it was just a one-off glitch..