Not sure if this is related but so far I have had the issue twice and done two factory resets. I connect my AirPods Max to my 2015 iMac 27", a 2020 iPad Pro 12.9, a 2017 iPad Pro 10.5 and a iPhone Pro 12 Max 2020. I also have a 2017 MacBook Pro running Big Sur. And occasionally I connect them to one of two of my Apple TV 4K.
So having the quick switch functionality is super worth it for me, and I really wanted over ear headphones, and I love the transparency mode for listening to music while in the house with people whom I talk with... Also the microphones work really great on video calls which are so much more common these days than they used to be.
Anyhow, whenever I do a factory reset I have problems pairing with my 2015 iMac 27". The iMac is running Big Sur and it is super fast with a 500GB SSD and 32GB of ram and a 4GHz quad-core processor. But for some reason if I pair to my iMac then it doesn't show on my other devices. On my other devices it says these AirPods Max are paired with another account or something like that... Even though my iMac is logged into the same iCloud account.
However if I pair the AirPods Max with my iPhone after a factory reset then it works with all my other devices except for my iMac. My iMac doesn't see the AirPods Max. But then sometimes after an hour or so my iMac starts to see the AirPods Max. Even though the other devices see the AirPods Max immediately. This is further frustrating because the iMac is the computer that I do my main work on.
I should say that I have Beat's Studio3 headphones, PowerBeats Pro headphones, AirPods, and AirPods Pro headphones and none of them have ever had this problem with my iMac vs my other devices as far as I know.
Anyone have any idea why that is happening? Thanks!