Have a look at my post here:
https://forums.flightsimulator.com/t/indiafoxtecho-t-45c-update-stuck-at-decompressing-potential-fix/384368
If it’s related to a stuck patch file handling, the deletion operation described a bit further in the post could fix your issue. I had the issue with both the T45C and the MB-339.
I’m a bit surprised though as the problem was fixed by MSFS few versions ago.