Unable to have internet on 2nd router

Hi everyone,

I have the internet that comes with antenna.
Cable from antenna goes into the modem, and from modem i got the internet to a switch.

From switch i have 2 cables out. one cable is short and connected to a wireless router (SMC). The other cable is around 35 meters reaching the other room, 2 rooms away. I connect another wireless router or access point at the other end of this long cable, but i cannot have the internet there. 1st router gets the IPs automatically but the 2nd cannot get, and says limited or no connectivity if I try to connect using this router's connection.

I tried to check the conductivity of the cable using my limited devices, not professionally. The cables seemed OK.

I connected another, shorter UTP CAT5e cable to the swithc and connected the 2nd wireless there and it works.

Do you suggest a solution?

Thank you in advance.