Hello,
I have installed GrapheneOS fresh on a google pixel 8a these days. At some point I tried to connect to a windows machine with bluetooth, and the connection fails. On the phone it says 'Connected' for 2-3 seconds, then it disconnects. The same behavior happens when I try to connect to an android phone: nothing phone 2a plus with latest updates.
Bluetooth connection does indeed work with my thinkpad l15 g1 running cachyos (arch distro) with kde plasma desktop environment.
I saw a bunch of other posts regarding bluetooth connection issues, but I don't know if they cover my case as well.