Along with the latest firmware you also need the latest version of GO4 in the smart controller. You can download that diretly using the lightening browser built into the smart controller. Just use it to go to the DJI website, then the Mavic 2...
Make sure you have the latest firmware version in the aircraft and the latest version of GO4 download right from the DJI website. After I did that and rebooted both, the error 180 was gone and has never returned.
I've had the code 180 error after updating the firmware for the remote ID thing. I then downloaded the latest version of GO4 for the smart controller right from the DJI website using the built-in browser. After installing that it was all happy...
There is absolutely no reason for anyone to avoid getting TRUST when it's free and you cannot fail it. The only downside is not having it when asked for it (if someone were to believe *all* pilots need a TRUST) but if you think about it, how can...