I appreciate you've tried some good troubleshooting already @Emilia_B12 👍
Can you also please try > Clear Cache Files from the phone's System Partition Section > https://www.samsung.com/uk/support/mobile-devices/how-do-i-clear-the-cache-on-my-device/ You may need to insert your earphones or hook upto a powered On Laptop to access the Clear Partition Section. This may help with lag or stutters as this clears the phone of old/unused or broken cache files.There is also a Repair Apps option in the Menu System too.
You can also clear the apps cache in Settings > Apps > Bluetooth > Storage > Clear Cache and if absolutely necessary Clear Data.
If you can't see the Bluetooth option then you'll need to turn on show System Apps which is found by tapping in the little lined icon at the end of where it says ' Your apps '
Also please run the diagnostic tool in your Samsung Members app.
Ultimately a back up and Factory Reset maybe the next logical step and or let a Samsung Service Centre take a look or send feedback via your Samsung Members app.
If I can be of any further help then please don't hesitate. Take care. 😎
Daily Driver > Samsung Galaxy s²² Ultra 256Gb in Phantom Black.
The advice I offer is my own and does not represent Samsung’s position.
I'm here to help. " This is the way. "