I'm basing off of the TX IDs I have from the hot wallet I was using to transfer funds from, and the receiving addresses all start with bc1q. So, I guess that means it's really the hidden feature?
No, you can't make that conclusion. Answer my questions from the previous post and tell the entire story please. A passphrase creates a totally different set of addresses, which would require you to move your coins from your non-passphrase protected addresses to the new passphrase-protected ones. Therefore, it can't be that you transferred your coins to a standard BTC address and then all of a sudden the coins went from there into a passphrase-protected addy or the software asks you for a passphrase. Unless there is a horrible bug we haven't seen or heard about before.
I am not a Trezor user, but I am pretty sure that the software isn't going to tell you:
hey, you have a passphrase-protected account. Can you please enter your passphrase now! How did you reach the conclusion that it's a problem with passphrases and not something else?