Hi there,
I'm Cherrelyn, an Independent Advisor, I'm here to help and I understand how annoying it is when your Bluetooth headphone audio suddenly drops in quality. Here's what I suggest that might help is just right- click the speaker icon on your taskbar > Sounds go to the Playback tab. Then if you see two entries for your headphones (one usually says "Hands-Free"), disable the Hands-Free version and keep only the Stereo output enabled.
Let me know about my suggestion, I'm here to guide you for further assistance.
Warm regards,
Cherrelyn