A friend sent 1 million USD to a Trezor address but is no longer able to find that wallet in his Trezor. He has asked me for help in recovering the funds. Initially, I thought that by adding the USDT token, the funds would appear. However, when I checked the ETH addresses he had on his Trezor, I found that they were not the same ones he had sent the funds to.
I suspected that he may have created a hidden wallet, but when I connected to Metamask to export the addresses, I was not asked for the passphrase of the supposed hidden wallet. I ended up creating one to test, and from that point, I was asked for the passphrase, which led me to believe that no hidden wallet was previously created.
My last possibility was that he may have accidentally reset his wallet (he mentioned that he tried to hide the funds) and when he reopened it, he might have created a new wallet. This would explain why the address he sent the funds to does not appear in the Trezor.
I have not reset the wallet yet and have used the seed phrase he provided me with. I am reaching out to see if any colleagues have any other ideas of what may have happened.