@killbill1 

Hi,

Is the "another router" also an Archer BE3600 ?

  @woozle hi, no it's a tplink tp- wr841n

  @killbill1 

Since you mentioned you can see the WR841N in the Tether app, I suggest you open the Tether app and verify the network name of the WR841N is actually different than the network name of the Archer BE3600. (because if the two routers used the same SSID, then they would show up as one network on client devices)

To do that tap on "Extended Network". In case "Network Name (SSID)" was identical to the network name of the Archer BE3600, then change it to something else, for example, add an "_Ext" ending to it.

  @woozle hi i can't see the extender network on the app

  @killbill1 

Your screenshot shows you are logged into the Archer BE3600.

To manage the Extended Network of the TL-WR841N you need to log into the TL-WR841N.

If you cannot see the TL-WR841N in the Tether app while your phone is connected to the Wi-Fi network of the Archer BE3600 (i.e. not a cellular connection and not connected remotely), then the setup of the TL-WR841N was most likely not successful.

  @woozle thank you for your help. the problem still persists

this what i have done

the last one is showing no internet in the new extender

  @killbill1 

  @killbill1 

So, if you connect a phone or computer to "TP-Link_E8FC_Ext", then they show some sort of "No Internet" message, right?

If that's the case, then maybe the technique used by the TL-WR841N to perform as a Range Extender is not compatible with the Archer BE3600.

What you could do as a workaround is to connect the TL-WR841N to the Archer BE3600 by using the "WISP" operation mode (second option in the first screenshot of your last post). This mode should always work. However, in WISP mode, client devices connected to the Archer BE3600 will not be able to communicate with client devices connected to the TL-WR841N.
 

  @woozle thank you for all your help,this is turning into a bit of a ball ache, i think i may just buy a dedicated extender