Hello  @MrPeralta 

Thank you for the case report. 

For multiple range extenders, it is recommended to reserve an IP address for each extender and use the IP address of the extender to access its web page.

As my understanding, there are more than one range extenders, the router may have trouble resolving the same domain to two different IP addresses in the local network. 

You could try to connect the network device to one of the range extender's Wi-Fi directly and use the domain http://tplinkrepeater.net to access RE and see if that makes any difference. While the best is probably using the IP address to access the range extender. 

Good day   @MrPeralta 

Thank you for sharing more case details.  To better assist with your case, we created a support email TKID220916000 , please check your email inbox. 

Please also share your network topology with us on that email  e.g. ISP X Router Model AX73 <Wireless>RE700X ; Router --RE700X(AP mode)

You could also share the method of creating the domain name 'http://repeater1/' this may help us look into the case further, thanks.

Feel free to let community know how it goes later.