When was the last time that Pi ran the latest Raspberry OS?
I ask because the 4 has an eeprom (unlike previous Pis) and they do update the bootloader often.
It just takes a first boot to update. Or you can follow this but either way you are going to need to dedicate an sd card.
And we are working on finding and supporting wifi devices here including the mt7921au.
I have read that the mt7921au has an amplifier that is not reporting to Linux and limits power to 13dBm on 5Ghz. I am in discussions with PANDA to see if they have solved this >2 year issue.