Another confused Asus + fibre user

[#1]

Hi.
I have an Asus DSL AX82U. Yesterday we switched to full fibre and I can’t get my router to make an internet connection with the OpenReach fibre modem.
I’ve read loads of threads on here and on other forums, but my router seems to be playing up in a way that’s different to many other posters.
If I go WAN>Internet Connection in the GUI, the Wan Type dropdown box only has one option in it, DSL. I can’t seem to find a pppoe option anywhere that will let me enter username etc.
Anyone got any bright ideas about why DSL is the only WAN type on offer?
I’m running out of life after 36hrs of going round in circles with this.
Thanks.

[#2]

Obvious question really, but do you have the Asus router connected to the modem via the blue EWAN port?

[#3]

How did you get the router to work on DSL if you did not have PPOE?

Have you used the Quick Internet Setup or are you trying to modify your existing setup?

[#4]

@Will7 

What happens if you -

• "Enable Dual WAN",
• set "Primary WAN" to "WAN"
• set "Secondary WAN" to "DSL" ?