@Joseph-TP Sorry , my mistake Should be port 1 and Port 3 , like the first pic

If I connect my ISP modem with 10gbs/SFP+ (Port 1) , and 10gbs (Port2) with my PC. it just causing the whole internet and WiFi ( 2.4g 5g 6g all of them) speed low and "really really really unstable",...