Additional meeting and call-related features and issues within Microsoft Teams for business
Unfortunately just had this issue again. Luckily this time I was able to jump straight on and put the admin prompt in for the audio driver troubleshooting which then reloaded the driver and the red cross went away and the audio options could then be loaded.
This hasn't happened for weeks so I had hoped it was resolved but clearly not.
I just wish Microsoft would work towards a fix for this!