I have 3 BT headphone things. They are all paired to both my mac and my iPhone. Something changed recently. If paired to my mac two out of the three play on hold beeps whenever my Google Meet meeting is muted. Or, and this is really annoying, if my computer happens to transition through some sort of sleep state in the other room. So, if I have them on at night and unless I remembered to disconnect my computer at the end of the work day, I am woken up in the middle of the night with random on hold beeps until I get up, go to the other room, and disconnect the computer.
On top of that they both of course randomly activate Siri in my iPhone (despite me setting Siri to only activate if I press the side button) and they both auto play the same random song.