[FIXED] I am having the same issue, but with a Jabra Evolve2 40 where the microphone stopped working after Windows 11 Update. Headphones still work fine. Microphone seems to be recognized in the sound properties, but Input Volume is always stuck at 0, and Format does not have any options in the drop-down box.
Restarting Windows does not help.
Uninstalling/reinstalling the device in Device Manager does not help.
New Jabra software/drivers does not help.
Switched to an older Plantronics Blackwire 3220 and microphone works fine on that headset.
Switching back to Jabra still does not work.
Edition Windows 11 Enterprise
Version 22H2
Installed on 6/21/2023
OS build 22621.1848
Experience Windows Feature Experience Pack 1000.22642.1000.0
I have fixed the issue by going to Device Manager and uninstalling all of the sound drivers as well as the Jabra Evolve40 device. Then clicking "Scan for Hardware Changes" to reinstall the sound drivers, the Jabra microphone is now working. Actually, what changed was the Intel USB audio driver is now just installed as (Generic USB Audio). I believe there must be some incompatibility with the Intel USB audio driver that was installed before.