This problem has not shown up until recently. Prior to the update today I was blaming the router as connection seemed to restore if I turned it on and off. But this no longer restores connection.
Firmware is up to date iOS 11.2.6
The message now seen (it is new - never happened before) is “There was a network error in accessing this album. Check your internet and try again”.
The iPad settings have not changed and are registered as connected to the ASUS router. And the iPad is connecting to the net and shows up in the home network