2.4GHZ archer c20
5Ghz connection on the router works fine but when connected to 2.4ghz the ping time on every site i ping is more than normal and goes up to 2000ms sometimes even on local servers. I have tried to upgrade the firmware hoping the issue to be fixed but it isnt fixed. the speed too on 2,4ghz is worse than my previous router. Can anyone tell me how to fix this issue the router i bought is US version and has only been 2 weeks.