Upgrade to ipad OS 13.1.2, cannot log in-- prompt to re-enter password results in "Verification Failure: An unknown error occured"

The password is correct.

The wifi network is connected.

The cellular network is connected.

The iPad Air 2 simply will not complete the setup, inputting the correct password over and over again results in spinning wheels followed by the above titled failure....and then just now the iPad restarted itself for some unknown reason...

This ios 13.1.2 software update is junk. Far too heavy for an iPad Air 2. Clearly buggy. Device is now un-useable. Very, very frustrated.