Lan Switch does not recognize Lan connection?

I have the following problem and I have a repeater on the 1st floor that is connected to the main router with a 10m long LAN cable. The repeater was mainly used as a switch. Now I got an 8pin switch and I have the problem that this switch does not recognize the incoming LAN connection from the router. I connect the cable again to the repeater and plug my laptop into the router. Everything works again.

Router LAN socket> cable> LAN socket computer >>> works?

Repeater> switch? No! Repeater or Access Point> Reinforced WLAN or LAN is sent via WLAN

Router LAN socket> cable> switch LAN socket> LAN socket LINK LED lights up >>> works? It does not work? Switch defective? Cable / connector defective.