When trying to install iOS 11.2.6 it doesn’t prompt for terms and conditions

I have tried to install progressive releases of iOS 11.2, the latest was 11.2.6.

each time it doesn’t prompt me to accept the terms and condition, just goes on saying verifying, then reboots my iPad. However when I then go to check what version is installed, it tells me that there is an update available 11.2.6 and asks me to download and install... over and over...

what am I doing wrong?