I just found out what might be causing our issues.
“Microphone not detected anymore? Sound settings or features not working? Check Settings > Privacy Microphone and test if “Let apps use my microphone” resolves the issue.”
https://www.ghacks.net/2018/05/01/all-the-issues-of-windows-10-version-1803-you-may-run-into/
I did that and now everything is working right as rain again.