Please ignore the hardware version and model as it won't let me put AC1750 range extender

I am trying to install this. Initially it wouldn't work via WPS buttons and if I tried via the list of networks the TP-Link wouldn't show up on the list.

I finally discovered it would be worth trying a hard reset which I did. Now I have the 5 and the 2.4 networks listed and can connect to either of them but it says "no internet".

I tried another hard reset but it made no difference. There definitely is internet and it is plugged in to the socket next to the router.

Thanks for any help.