I have an issue while using my Note 9 and my samsung ear buds. At random times the sound out put will change, it will go from coming out of my buds to my phone. I can't change it back unless I either disconnect and reconnect them or turn off and on the bluetooth. It also happens when i take them off real quic to rub my ears (after prolongued use of them they bother me a bit). On my Samsung wearables app it still shows they are connected, but when I for example, try to lower or raise the volume, it shows that I'm raising or lowering the volume of the media *on the phone not on the headphones). Is there a settings i need to change? Or possibly a switch of sorts? I verified permissions and made sure everything was up to date.
Have you confirmed the software for the buds is up to date in the wearables app? Have you attempted to reset the buds? Try that and see if that helps any.
Tap About earbuds > Reset earbuds, and then tap Reset.