ok I will try that, and will update here. But just to clarify: Audio is working fine. i.e. laptop inbuilt speakers, only when I connect to my usb headphones it’s not working.
I have tried this, but it’s still not working. I have removed (copied to some other location) the files inside /etc/udev/rules.d/ after the reboot laptop doesn’t shows-up any volume icon. As a result, I had to copy those configuration files back to /etc/udev/rules.d/.
But here in GNOME, this is not the case, even when selecting the “Headphones - Headset [PC 8]” option from Settings → Sound, it’s not working. (screenshot attached).
If you had pipewire installed in Fedora 32 or 33, it may stop working on upgrade to Fedora 34. If this happens to you, we recommend moving all *.conf files out of /etc/pipewire and reinstalling pipewire with sudo dnf reinstall pipewire pipewire-pulseaudio . You will then need to re-apply any customizations you had made to the configuration files.
I am also facing issues with Fedora 34 Workstation edition and my usb headsets. But my headset works for sometime after a reboot. I think it keeps working as long as it is in use by some application but if it is left idle for some time it stops working. Restarting the pipewire service fixes it, as suggested by @ankursinha in reply to my question.