@Paul_S84 

You need to contact live support by making a post on their Community forum, they will then do something to the ONT settings at their end and your router will then connect, as it is it will never connect because you can't set the Vlan ID to 0.

This is to be able to dump the TT router and go direct to the ONT from the AX72, if you use it as an AP then there is no need all you do is connect them with an RJ45 cable cat5a and above and give them different 192 numbers, example R1 TT 192.168.0.1 & R2 AX72 192.168.0.2 making sure you put the AX72 into AP mode as well and turn off the wifi on the TT router.

Look out for the support agent called Chris, very helpful and knows exactly how to help you.

Hi  @Paul_S84 

If you are configuring Archer AX72 for the first time and your internet service provider is talk talk, please confirm your internet configuration information with talk talk. For example, username, password, VLAN ID (this information needs to be provided by talk talk)

It is recommended that you download the Tether APP for configuration. For the specific configuration guidance process, please refer to:

How to set up TP-Link Wi-Fi Router on Tether APP

If the router has no internet or internet is offline, please try the steps below:

Orange/Red Internet light on the router:

    1. Identify whether your router or ISP(internet service provider) is the problem by connecting your PC directly to the modem to check the internet access. If the Internet is not working, contact your ISP.

    2. Turn off the Modem and the Router, then power on the Router, turn on the modem once the router is fully powered on.

    3. Log in to the web UI via http://tplinkwifi.net and follow the Quick Setup to set it up.

4. Please go to Advanced > Network > Internet > Mac Clone to clone the MAC address of your PC.  Please follow the FAQ:

MAC Address Clone on my TP-Link Archer Router

  @Bogle I was worried that would be suggestion. I was hoping it could be something done myself via settings.

Really don't enjoy dealing with TalkTalk!

  @Paul_S84 

Yeah I get that, it's easy however, avoid the chatbox or you'll get a bot replying to you, go to the community section and create an account then post in the Full Fibre section, look for Chris he's still active and explain you have bought a 3rd party router but want to set it up without the TT router but believe you need to use a Vlan ID of 0 (zero) which TPL routers do not support, an Asus one would allow this but they're constantly having to issue new FW for their routers, a lot of the other competitor brands are the same and most 50% more than TPL charges for the same level equipment in a lot of cases, Asus are a bogey brand to me anyway.

Anyway once the support guys & gals see your post they will respond to you within 2 days excluding weekends, I suggest you seek Chris out as he's sorted this out for quite a few people, follow his instructions once he tells you he's made adjustments, it might not be the same for all as some ONT's are BT and others Cityfibre but I'm confident he can sort it out for you and the new router if you configure it right will shout across the house for you, obviously if you try to have too many connections things slow down so make sure you use the OFDMA and MU-MIMO settings along with 160 for the 5ghz and select airtime fairness if it's an option rather than QOS, also turn off WPS & UPNP as soon as you hit the set up pages.

Once Chris or one of the other support team (Arnie may answer you) says they've adjusted setting for you you should be able to just hit the wizard and it'll sort most of the connection side out for you automatically regarding MTU and Dynamic IP etc.

If you go ahead and they get you connected come back and update us as this will help others in the future if it crops up on a search engine as solved.