Hi again. Thank you so much to everyone for entertaining this again. I really appreciate it. You have no idea how much. I have pulled out the codes and went through the characters to confirm they are clear and correct. They are clear as day. The title he used above the key was underlined Bitrexx Secret Key. It is very frustrating.
Hi again. I remember all your previous threads. It seems like you have followed all the right steps but are still unable to access his accounts unfortunately. It sounds very much like you have the incorrect keys. Perhaps your uncle reset the 2FA on his accounts after making those back ups and failed to update his back ups.
There are two possibilities here. The first is back up codes are actually correct, but are generating out of sync 6 digit codes for you. Have you tried restoring them on different apps? Have you tried restoring them on different devices? If you like, you can PM me one of the back up codes and I can restore to see if the 6 digit codes I generate match the codes you are generating. (I can provide a PGP public key if you wish to encrypt them first if you know how to do this, although there is very little someone could do with the 2FA back up code only, not knowing your uncle's account name, email, or password).
The other possibility is as I said above: The codes are incorrect. If that is the case, then the only possibility you have for gaining access to the accounts is to email Bittrex and Coinbase, proving legal documentation that your uncle has passed away and you are the heir to his coins, and then complete KYC to prove your identity, and hope that they unlock his accounts for you.