20.2 Can't connect to pair of Bluetooth speakers ONLY when they are synced to each other

[whiggity]

I'm running Mint 20.2 on an ASUS machine. The speakers in question are AOMAIS, which can be used individually or wirelessly connected to each other to serve as left and right for stereo sound.

Blueman has no trouble connecting to each speaker individually, but as soon as the speakers are synced with one another, trying to connect will give the error "Connection Failed: Host is down" or "Connection Failed: Resource Temporarily Unavailable."

I can occasionally sort of "trick" Blueman into connecting to both speakers by connecting to one, then turning on the other and linking it to the first speaker--but the audio quality is stuttering and rough. This also doesn't always work. More often, trying to link the second speaker to the first results in both being disconnected immediately. Which result I get seems to be totally random, given the same test procedure.

I've been dealing with this problem for a couple years. I've been updating Mint on a regular basis since 18.1, and the synced speakers worked with no issue until the upgrade to (I believe) 18.3, at which point this error manifested and has persisted ever since, across two different machines. I don't believe the problem lies with the speakers. Other devices, such as my phone or my Windows partition, have no trouble connecting to the speakers when they are linked to each other.

Apologies if this is sparse on info. Let me know if there's anything else I can clarify.