I was thinking that or a broken switch. It is connecting intermittently.
The conventional bluetooth wouldn’t change the settings, that would go through the BT LE connections. I suppose if they both do it while the other one is off, it could be something weird from the app, but I really don’t think that’s the case.
I hope it is a little gunk wedged where you can get it out. Look with a magnifying glass if necessary to rule out anything you might be able to clean out before you send them in.
Sorry…
WH