V1620057240707 , via OnePlus 7 , May 5, 2021 : Having call voice issues with Android 11 upgrade on Oneplus 7. Read somewhere that it has a workaround for oneplus7 pro with turning on hearing aid comparability, but this option is not available for OP 7. Both I coming and outgoing calls go to bottom speaker directly. Switching to speaker mode does it fix the issue. Changing side button to Ring, vibrate, silent does not fix the issue.