I had the same thing happen to me when I reached bronze the flight counter 'reset' even though the flights taken showed more than enough (12 in my case). I was not at the end of my year but the app said 0 out of 4 flights completed.
I checked my membership page on the full website and it had 4 out of 4 completed, I think it must be some sort of 'glitch' but when I had enough TPs my membership was promoted to silver without any intervention on my part.