CHAP authentication failure

[#1]

Hi

I moved from EE to Plusnet on 21 December, and have had no service ever since.

An Openreach engineer came round today and swapped the ONT, which did not help; he suggested we need a new hub, and one has been ordered.

I don't think the hub is the issue.  Every time I try to connect - with correct ****@plusdsl.net username and password - the technical log shows the connection process starts successfully, but fails at the CHAP authentication stage.  The challenge response is invalid, the CHAP authentication fails, and then the connection drops:

00:12:19, 01 Oct. PPP: CHAP authentication failed

00:12:19, 01 Oct. PPP CHAP Receive success : authentication failure

00:12:19, 01 Oct. PPP CHAP Receive Challenge

I'm now waiting a few days for the replacement router to arrive, fairly confident that won't sort the issue, and apparently the step after that is to send another Openreach engineer for a second opinion.

It seems really likely to me that the issue is with the CHAP authentication failure, and I wondered whether anyone could suggest any troubleshooting steps to confirm or address that issue?

Thanks

[#2]

Same problem and fix some years ago

https://community.plus.net/t5/Full-Fibre/Unable-to-connect-since-Saturday-FTTP/m-p/1691344

[#3]

Thanks, but I'd already seen that one.  Tried changing my password a couple of times, and that didn't work.  Have had many conversations with Plusnet, and every time they've assured me my account is all correct, so it seems unlikely that broadband would need adding to the account (it's a broadband-only account).