Using own router - no internet

[#1]

I was using my own ASUS ZenWifi router with BT and all worked fine over PPPoE.

I’ve added my username and password to switch to plusnet, and although my ASUs router shows as having an Internet connection, I can’t load any sites, even with something like 1.1.1.1 as DNS.

Any suggestions as how to get the last part done?

[#2]

have you tried the guides here:

 https://www.plus.net/help/broadband/broadband-connection-settings/

[#3]

BT doesn't need a username and password.

Plusnet does.

Has your service definitely changed to BT and does Plusnet's router work?

The link above is good but one thing to note (and often catches people out), if you have "full fibre" (so an Openreach ONT in your home) use the "What settings should I use for a fibre router that's connected to a BT Openreach modem?" instructions.

There are no VLAN tags needed.