Magic Mask 2 retracks at each export

I noticed that every time i do an export all Magic Mask 2 need to be retracked.
This happens also if i don't touch anything in the tracked clips and simply adjust something in soundtrack and so on. No output resolution change nor timeline resolution change.
Each time i export the retrack takes about 40 minutes in my project.
Is it something relatable to the beta or does it simply work this way? If this is the case, magic masks become less attractive...

The only time I've seen need to re-track is if the link between what you tracked and cached frames is broken in some way. I don't know what exactly you did or didn't do, but probably unknowingly you did something to break the link. Otherwise its not normal to ask for re-tracking. Only when you change the source on which tracking was performed. Make sure you are not invalidating something. If you don't know what, make an empty timeline and put some clips on it and try to re-track common steps until you invalidate the track. Than you will know. But won't have to do whole re-tracking, just do 10 frames or something for testing.

Maybe i did something strange in pre-clip graph without noticing it.
The last re-render i performed didn't need retracking.
I'll put more attention on this in future hope being able to understand what's going on.
Thanks for your reply!