iPad software update doesn't find iPadOS 16, says 15.7 is the latest

I have an iPad Air 5th Gen that upgraded to IOS 15.7 today, however further checks for an update doesn't find IOS 16.x.

I have tried all of the suggestions across the net including reboots, resetting network settings, checking from Finder on my Mac with the iPad tethered via USB-C.

Every time it reports 15.7 is the latest version (as of Sept 30, 2022).

I'm not interested enough yet to try a full factory reset!

Thanks for any suggestions.