Chunks don’t really work in Ardour. They’re an unfinished feature.
The .t’s i guess come from timestretching regions. Having multiple timestretches in your region name suggests you’ve don so repeatedly. This is ill-advised. The stretch algo is usable at best. Consecutive time stretches to a region will only add on top of previous glitches produced by the algo. I suggest you always time-stretch the original region to the length you need it to be. That way you will need to run the audio through the algo only once.