If you can afford it, I personally highly recommend just buying two USB-C hardware Yubikeys and storing it on there. Built in back up and if you put it on your keyring, it’s always nearby. You can still use your phone to access the code as well.

Not exactly super helpful for solving this problem but since you’re already going to have to reset or get new accounts, it’s a good time to switch over if you’re interested.

What’s probably happening here is your adapter is signaling some button press when you connect it that’s popping up the Assistant. Only way to fix that is to get a new adapter since you can’t manually disable that input from triggering the Assistant without root.

However, you can completely disable the Google Assistant from appearing at all via:

Settings > Apps > Default Apps > Digital Assistant App > Default Digital Assistant App > None

That should fully disable it in all regards and it’ll never pop up again.