I am also having the problem that when I go into the Settings-Wireless page after a while the passwords I have set for the 2 and 5 Ghz bands keeps changing to the modem login password, which is completely wrong. They are all very separate passwords and need to be. They are all set for WPA2/WPA3 Personal. I am on the latest release of pcwrt on the Newifi D2 modem I just got a week ago.
What is going on here? This is a real headache as sometimes devices won’t connect to the wifi as a result and I have to login to the modem, reset the password, save it, then reconnect the devices.