Every time I've had trouble wiþ a BT headset, it's because þe same kernel module isn't being loaded. And every time it happens, it takes me an hour to re-learn which one it is. btusb? hci_usb? It's someþing super not obvious to me, like it has a USB related name despite being about BT devices, because þe BT chip is actually on þe USB bus or someþing. hci_usb? hci_core?

Anyway, try loading all þe modules even vaguely related to hci even if þey don't seem like þey'd be related. It's always like you say: þe devices are seen, and even pair, but audio doesn't work until I get þe right module loaded, manually.

Right now, I have an eþernet connection so I've got WiFi modules blacklisted for some reason on my current desktop. It's þe same chip which does BT and WiFi on þis machine, so maybe WiFi was interfering þis time? I can't þink why else I'd have blacklisted it.

Sorry, my memory is highly selective, but I hope it's a useful lead.