ahhh yes!! It worked! Thank you!
Hey I was having the same issue, I found a fix. Or at least this is what worked for me.
Go to settings > connections > more connection settings
Is nearby device scanning off? If so turn it on.
If it is already on, toggle it off then reboot your phone.
When your phone finishes rebooting re toggle that setting back on.
That's what worked for me.
Dint work with my car audio. My oneplus used to work seamlessly with my cars audio system. As soon as i would start my car with audio source as bluetooth, music would start playing automatically (amazon prime music or you tube music app). Samsung o/s is so bad.