MacBook Air won't play audio through bluetooth headphones

Suddenly, a few days ago, my 2020 M1 MacBook Air stopped playing audio through two of my bluetooth devices. These two headphones have been connected to this computer for 3 years, and have always worked fine. They continue to work fine when paired with half a dozen other devices, including other Macs — and other bluetooth devices continue to work with the MBA. For a couple hours yesterday, they worked fine with this MBA again, randomly, with nothing changed. Today they're not working. Again.

When these devices are connected, there is no sound — not from the computer, not from the headphones.

Both the Mac and the headphones confirm they're connected.

Bluetooth settings on Mac confirm they're connected.

Sound settings on Mac confirm they are the selected output and input device, and "Play sound effects through" is set to Selected Sound Output Device.

There have been no software updates, no new software installed, no changes of any kind.

I have rebooted everything. I have unpaired and re-paired. I have forgotten the bluetooth devices on the Mac, and paired them as new. I have tried different users in the Mac. I have tried Safe Mode. No dice.

And again, they work fine with other Macs running the same OS.

2020 M1 MBA running latest Ventura

JLAB Rewind headphones

UPDATE: Have just discovered another device having the same problem. Only one of my 5 bluetooth headphones/earbuds currently works with this computer.

Would love to hear suggestions!

/Note: cannot currently upgrade to Sonoma — but again, cannot reproduce this problem on devices also running Ventura, so clearly Ventura isn't the problem.