When configuring a range extender for the first time, you have to consider that it's DHCP server is set to Auto which may cause some network issues. While this was made to improve the user experience...

@DanielDT If you don't have access to your router web management use the following IP address for the RE 192.168.1.253 (Direccion IP).

@DanielDT That means the technician changed your router LAN IP address subnet to 192.168.1.0/24, i.e your router has LAN IP address 192.168.1.254. Do you have access to your router web management -...

@DanielDT Look at my post $4 the RE gateway IP address is your main router LAN IP address, i..e 192.168.0.1 (if you use the 192.168.0.0/24 subnet). Once you set the RE with static IP address...

@garasakal If it's not properly configured TL-WA850RE can cause similar behavior. I would recommend to set TL-WA850RE with a static IP address like 192.168.X.254 (X - depends on what your VR400 LAN...

@bilb1 Use this FAQ to troubleshoot your issue. If it's about a DSL modem router go through this FAQ.