I had been facing issue with Bluetooth devices that it got connected with handset but audio was not there after updating android 10.
And I know many of you facing same.
So here is the solution which worked for me 100%.
" If you have developer options activated, then deactivate and restart the phone. This 100% fixed the problem for me and some others. If not, then try activating developer options, disable the audio routing to usb option and the restart. Might work too."
All thanks to my old mate in this community @Rahber Ali
for giving brilliant solution.