Model: Archer C50 Hardware Version: V4 Firmware Version: V4 I have Archer C50 dual band router using 2nd Router Operation mode is Wireless Router But 5ghz not give me 100 Mbps and some time Main route

I have Archer C50 dual band router using 2nd ROuter Operation mode is Wirelees Router But 5ghz not give me 100 mbps and somen time Main router 2.4ghz router gives me Up to 100 mbps and static 5ghz wif