Update:
I contacted Phonak support. Turned Bluetooth off. Forgot main R hearing aid in Bluetooth.Performed a reset of network services which was supposed to solve issue. Powered on and connected R hearing aid. Next day bad call quality was back (note did not power iPhone off/on).
The only thing that I have found that WORKS is power your iPhone off and then on each morning. This has worked well for me. I’m a light user so someone on the phone all day may have a different result.