There are some big bugs in MIDI handling and editing. Take a 4bar sample from a 3rd party supplier and dnd it onto a MIDI track. The copied track is NOT exactly 4 bars long but slightly less. This ensures that repetition by expansion slowly goes out of sync with the metronome.
As a follow-up from Windows bug found #1 the same problem also appears with a 4-bar audio snippet with the snippet going out-of-sync after the 3rd or 4th repetition.
Version is 10.2.0.64 build 9210
As a follow-up from Windows bug found #1, splitting the out-of-sync MIDI parts using the “Ungroup Parts” option to split more parts will lead to parts being deleted and/or moved. Using the undo option has no effect as the save points have been eradicated.
Closing and reopening the project restores the editing to the bug situation.
Please attach a sample MIDI and audio loop that shows the issue with the incorrect loop length, or send it to support@ntrack.com
When adding audio parts, the wav file needs to contain tempo metadata in order for it to loop correctly keeping tempo, and the ‘part speed follows song bpm’ option in the tempo/key upper right widget must be active (it should be active by default for wavs with tempo metadata). Can you see the issue also occurring with audio or MIDI loops from our library? Which ones?
I haven’t been able to reproduce parts being deleted when ungrouping parts, also for looped midi ones, but I’ve reproduced an issue with splitting parts and using the undo command, which appears to restore an incorrect intermediate state. Undoing further restored a correct previous state. We’ll be fixing this in the next update.
If you can reproduce ungrouping parts leading to parts being deleted please send more detailed instructions on how to reproduce this or post a short video showing what’s happening.
Flavio.
P.s.: I’ve grouped three of your posts on this post, please post followups replying to this post instead of creating a new one unless it’s an unrelated issue 
Hi Flavio
I am unsure if stacking bugs into one problem report is correct. Personally, after many years in software development and testing this practice leads to bugs being forgotten, missed or remaining unresolved. However, as I do not know what kind of problem-management system you use, your testing process or the resulting statistics, I will keep an eye on the resolution of each one of these stacked bugs.
Graham