u/Affectionate-Rub9342

I bought a LTE/5G Sim Router for my mother house(she doesn't need much bandwith and I have an unlimited data plan so it's like 10$/month for the sim card), I had it plugged to a standard router(in the wan port) and it worked perfectly for a while. About a month ago internet just died for some unknown reason, I reset both the ZTE and the Tenda router but still won't get internet. When I plug the cable from the ZTE directly in my laptop I get internet and everything is working fine, but as soon as I plug it in the home router it gets no internet. I tried everything I could think of but nothing worked. If anyone has any idea, I'm loosing hope here.

Sim router: ZTE MC7010CA House router: Tenda AC6