Dealing with wonky Bluetooth call quality can be such a headache. I remember when I upgraded my phone and suddenly everyone sounded like they were speaking through a fish tank! I stumbled upon an article (https://www.mightycall.com/cloud-call-center/) about troubleshooting call quality issues, and it got me thinking. Once, I had a similar problem where calls were crystal clear one moment and then all distorted the next. Turns out, it was a glitch with the Bluetooth connection itself. I had to unpair and repair my phone with the car's system, and that seemed to do the trick. Maybe give that a shot and see if it helps improve the call quality.