Why does wiping the /cache partition keep fixing my problem? My phone Droid Turbo 2 on Android Marshmallow for some reason my Audio in and out keeps going out.

Wiping the /cache partition seems to fix the problem most of the time.

Any idea why this might be the case? Could this be related to why it takes the phone so long to turnoff and reboot?
Gave up with debugging this. Fixed by rolling back pre-android 6.x