Try wiping system cache
Turn you phone completely off
Hold volume up bixby and power till you see the recovery menu
Select wipe system cache using volume buttons and power
Boot into safe mode (all user installed apps disabled) and see if another app you installed is affecting BT.
Hold power till you see power off
Hold power off till you see safe mode
Back up your data and factory reset your device.
If these 3 options dont help, then its most likely a issue with the BT device or your phones hardware.
No these are just recommendations when you have a system problem to try and determine the source of the issue or just common fixes that can help when your experiencing an issue like this.