I tried all of the suggestions above with no luck. Shore power voltage is good.
Disconnected the solar controller for 30 minutes and the same: solar charge light is on but battery charge light not flashing with voltage at 12.3.
Pulled out the Iota charger. Open circuit voltage is 6.5 which is an odd number but clearly it's not going to charge. I do not see any kind of fuse attached to it.
I guess I'm hooped. It seems like both the solar controller and the Iota charger failed at the same time. That seems highly improbable so I hope I haven't missed something.