For some time my Dayton UMM-6 mic has not be prompting to enter the serial number to calibrate and shows up as a generic plug and play mic.
I've seen the help note here suggesting to unplug and replug it a few times, but that doesn't seem to help.
My other mic, the Umic-1 works fine.
I thought perhaps it might have been that I'm using the original USB camera adapter with a 30pin to lighting adaptor. But that still works fine with the Umik-1 on an iPad Air 2.
And I see the Umm-6 still behaves that way on an iPad Pro 10.5 with the current USB camera adaptor.