Asus DSL-N16 Chap Authentication Failed

[#1]

Hey, hoping someone can point me in the right direction here 

it's been SOOO long since I have set this router up, need to make sure everything is entered correctly.

I have Basic ADSL (not fibre) 

Using Asus DSL-N16

I originally set this up a few years ago and its been sat nicely until maybe 2 months. our line got disconnected (turns out BT gave the physical connection in the exchange to someone else) 

Without checking for a Dial tone, I reset the router to default, thinking it was broken.

I have a strange problem, on 1 page, the link shows UP - But without providing an IP From Plusnet

but in the connection log shows this below

I spoke to Plusnet who say I am using the wrong password, This is not possible 

We even reset the password while on the phone & Still the same error 

Settings taken from 

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

2) personalised connection settings within my account

3 screenshots added, I have the Authentication set to CHAP, it it just a screenshot from earlier today 

Router log 

2023-03-28 18:53:53 kernel: mt7510_config
2023-03-28 18:53:53 kernel: tc3162_atm_close done
2023-03-28 18:53:53 syslog: LCP down.
2023-03-28 18:53:57 syslog: LCP is allowed to come up.
2023-03-28 18:53:57 syslog: qos.txtp.pcr = qos.rxtp.pcr = 0
2023-03-28 18:53:57 kernel: mt7510_atm_open
2023-03-28 18:53:57 kernel: vpi: 0
2023-03-28 18:53:57 kernel: vci: 38
2023-03-28 18:53:57 kernel: mt7510_atm_open vc 0:
2023-03-28 18:53:57 kernel: ATM over ADSL mode init
2023-03-28 18:53:57 kernel: dslUpRate: 1727
2023-03-28 18:53:57 kernel: enter pppoatm_init_hook function
2023-03-28 18:53:57 kernel: mt7510_init_PPPOA
2023-03-28 18:53:57 kernel: Init VC 0 MPOA Function
2023-03-28 18:53:57 kernel: MPOA Mode: MODE_ROUTER
2023-03-28 18:53:57 syslog: Using interface ppp0
2023-03-28 18:53:57 syslog: Connect: ppp0 <--> 0.38
2023-03-28 18:54:01 syslog: CHAP authentication failed
2023-03-28 18:54:01 syslog: CHAP authentication failed
2023-03-28 18:54:01 syslog: CHAP authentication failed
2023-03-28 18:54:01 syslog: LCP down.
2023-03-28 18:54:07 syslog: Connection terminated.

[#2]

It does seem to be an authentication problem.

Check the username & password by logging into the member centre with them.

If that's OK then try the following credentials in the router ppp settings

Username - bt_test@startup_domain , blank  password

If that works then try

Username - bt_test_user@plusdsl.net , blank password

Let us know what works and what doesn't

[#3]

Already able to log into the online account using the username & password 

however the online account is 

username 

the dsl connection is username@plusdsl.net

We even reset the password today

[#4]

The router wont allow me to save the settings with an empty password box

[#5]

however the online account is 

username 

the dsl connection is username@plusdsl.net

thats correct but it proves the basic username/password are correct

You coukd try a non blank pw for the test usernames, its been so long since i used them i cant remember 

If that will work.

Has tge connection ever worked since the fault ( disconnection) was rectified ?