@woldsweather I was on to TPLINK for 2 hours. I realised I had been pressing the button above the reset button.

However he couldn't get me connected and finally said he would send me a link for suppoert with the advanced problem team.

The link he sent was foir setting up an Access Point. I'm surely not sdetting up an access point?

I went through the quick set up guide in the tetherapp lots of times. It says success full then on the next scree says No Internet Access.

He also told me to plug in the ethernet cable I had takern out of the Plusnet router and put it in one of the yelklow ethernet ports. Thats surely not right surely it's the blue port?

  @woldsweather 

It depends on what you are trying to achieve.

Is your goal to discard the Plusnet router altogether and replace it with the Archer AX55 or are you keeping the Plusnet router and just connect the Archer AX55 in series?
The latter option would be much easier to realize.
 

By the way, which one of the Plusnet routers are we talking about? The Plusnet UK website lists four available devices, Plusnet Hub Two, Plusnet Hub One, Plusnet Hub Zero, Technicolor 582n.

  @woldsweather 

I never thought of anything other than replacing the Plusnet router. I wanted wifi 6 and a better signal around the house and garden.

  @woldsweather 

Ok, so you unplugged the Ethernet cable that was connected to the port labeled  WAN  of the Hub Two and then plugged that cable into the blue port of the Archer AX55, right?

Next you would need to configure the Internet connection of the Archer AX55 according to the instructions on this webpage:

https://www<dot>plus<dot>net/help/broadband/broadband-connection-settings/      (you need to replace <dot> with . because I can't post external links here)

  @woldsweather 

Set up now one chacter of the log in password to Plusnet that I though was an ! was something else.  Could have saved me 6 hours of grief¬

Thanks everyone