The next time it happens, reboot and then run sudo journalctl -b 1 -e -x. What errors are logged?

Fun fact: you probably know that wireless earbuds have a primary/secondary relationship, where the audio source connects to just one earbud, which then relays it to the second. Interestingly, this isn’t the case anymore with Bluetooth LE audio, where the phone manages the connection to each earbud independently. even though the phone does more work, it uses less power because the codec is more efficient