Can't provide internet problem

[RFarago]

I have changed the BT Smart Hub 2 to an ASUS RT-AX52 router.

Everything went fine with the set up. On my mobile I can see all connected devices, however I get an error message that this connection can't provide internet and suggests a WAN problem. There is no issue with the cable, I tried several.
Any idea what went wrong? 

[licquorice]

What broadband service do you have, full fibre or FTTC.

If FTTC, that device won't work as it is just a router and not a combined modem/router.

If FTTP, have you configured the PPPoE settings with the generic credentials of username bthomehub@btbroadband.com and password BT?

[RFarago]

I have Full Fiber

And yes, I have used the user name and password as you said.

[Crimliar]

The WAN section of the settings on the Asus router should look similar to:

[RFarago · Accepted solution]

I have reset the router and done the set up again. 
This time I was offered a firmware update.
Once that was done everything worked fine.
Thank you for the quick replies.