Thanks for the link. There were no changes since the last performance. I updated to the latest fader application when it first came out a few weeks ago. Gig last week was fine. No issues. First three quarters of THIS gig was fine, with no issues. Input metering WAS working. Showing good signal, only, it wasn't coming through the mixer and into the amp until the reboot.
The only thing that was different is that one of my band mates brought his iPad for the first time and did not dock it in the mixer, but just connected through the WiFi. But that was earlier before we even started the show. When the screen came up with the choice of how to connect, he handed it to me and I chose the DL-1608 button as opposed to offline or iPad storage. It's possible that the saved shows were wiped out at that point, I suppose, because I really had no reason to go back and check them until I developed the lead mic level problems in the third set. It still doesn't explain why my mic level dropped, even though it was showing a strong input level on the iPad mixer display....