@Skolgatan16 AC1200 is not the model. It should be something like RExxx. You could refer to the troubleshooting guide here: Unable to Connect to WiFi Extender or Saying Incorrect Password

@Chanda_321 What is the model number of your range extender? If you can't log into the web UI, maybe you could try the Tether APP. The configuration via Tether APP is quite easy.

@ksaro1 Did you try to change the DNS under the DHCP server to 8.8.8.8/8.8.4.4?

@fischema You should still set 400m/s or the internet speed from the first PX50. If you put 100m/s, then the whole PX50 mesh will be limited to 100m/s.

@ddlnegocios It seemed like it is a service provider model and is your ISP allowed the third-party router? I googled the X500V manual and it seemed to allow to turn off the DHCP server under...

@Zeinalfa708 You could find the hardware version here: How to find the hardware and firmware version of my TP-Link device The USB port on the old windows might be bad and please change to a different...