Hi, for the past month I've been having connection issues with RE700X. I bought it in May 2025 and apart from occasional IP conflicts it was working fine. Now it won't connect to the Internet, in tether app it says there is no connection through the main network. The thing is, the main network works fine - I connected to it directly and while not fast, the connection works. 

Nothing about the main network's hardware has changed recently so I am confused why the issues have started appearing.

I tried almost all settings I can in Tether App - I started with "Auto" settings and also tried to set LAN and DHCP manually using this article:

https://www.tp-link.com/en/support/faq/2965/

And while it worked for a couple of days, the issue has reappeared. 

Is there something I can do to better diagnose this problem? Maybe my settings are wrong? I attach screenshots from Tether and a result from fast.com of my main network. 

Unfortunately I have no access to the main router - all I know is SSID and password (don't worry, I'm not stealing the wifi, this is the only way I can get fiber Internet on my rented apartment and has been approved by the owner). There is no way for me to change main router settings like channels, separate SSIDs for different frequencies etc.