I can't speak to other sequences but this is the sequence I use and I have no problems:
First I delete SUBARU from my phone's bluetooth, then I turn bluetooth off on the phone.
Second I do a full system reset of the Subaru's infotainment system - if you don't want to do that you could simply delete all the devices from the infotainment system but I always do a full system reset, which requires re-setting a bunch of stuff afterwards.
With bluetooth still off on the phone, and no phones registered to the car, I start the car and let the infotainment system boot.
After it's booted, I plug the android phone into the USB and it will ask me about starting android auto and I say yes to everything. Mind you, Bluetooth is still off on the phone. As you set up Android Auto bluetooth will turn on automatically with no need to "pair" it.
After all of that is done, the contacts and everything work fine. Have someone text you and at some point (strangely usually after I shut the car off) your phone will ask to give permission for text messaging.
Also do you know if you have software version 980 in your car? Some 2021 cars came with version 500 instead of the newer 980.