Teams only displays "Customer setup" when starting up

So we have teams for business and are getting a number of users with problems in teams. This most commonly occurs after the device has recently been powered on or restarted but can also just occur randomly. 

Essentially what happens is that a user will not have access to their audio devices or cameras, but only within teams. These devices are accessible in every other application at that time and the failure in teams persists across both desktop and web versions. Weirdly, if they join a meeting in this state they can *hear* audio but not actually speak or manage the sound at all within teams. If you look at devices it explicitly shows only Custom Setup and No camera found during this time. 

If you wait, anywhere from a few minutes to half an hour, the devices will come available again. 

We've tested the following:

• restarting the device 
• restarting teams
• reinstalling teams
• clearing the local cache 
• ensuring nothing else is using the sound devices or camera
• making sure everything is updated 

This effects users at random, no consistency between effected users and unaffected users. Additionally I suspect all users are equally effected but not all attempt to make calls/join meetings whlie impacted so they never notice the problem. 

Any help is appreciated.