The funny thing about the article I read on Reddit is that the support isn't good enough and they make ridiculous requests:
I tried to search for that proof of destruction thing mentioned by one of the users but I could not find one from Trezor. The only reason I can think of is what has been mentioned privacy above. You should be able to return the device securely after resetting it though. I never heard any wallet company request your private key to process a replacement. I think that the user misunderstood something from the support, or the support is just extremely terrible at explaining things. If that was not the case, then damn, you'll probably feel safer buying a new wallet instead.
I also have a model T, and there are problems with incorrect PIN entry, especially when I have not used the device for a long time. What is the reason, I have not yet found out
If it is similar to what OP or others on the threads mentioned above, one of the likely reasons is a faulty screen. I doubt you can get a replacement for free in this case since it sounds like you bought the device long ago. CMIIW.