HI

Iam Using tp-link wifirouter archer a9 .

Iam Facing Slow Speed on Wifi2.4ghz  on all tp link archer a9 devices,having extreme slow speed and unstable connection .

Iam using isp connection having speed of 100mbps. In lan iam getting 100mbps speed but in wireless 2.4ghz iam getting 25mbps for 100mbps and some times it can drop to 0.5mbps and 1mbps speed 

i tired changing channel width from 20mhz to 40mhz and  change changes   like 1,6,11  but nothing helps  but in 5ghz iam getting full speed

i tired trouble shooting steps like 

i checkd the speed on both phone and laptop .and disconnected all devices the wireless speed iam getting is 25mbps out of 100mbps in 2.4 some times drops to 0.5 to 1mbps

i replaced router through rma department but same issue is present  i thing the issue is in firmware

yes is tested speed on the speed test by  Okla i switched 20mhz to 40mhz channel width  but same speed

i disabled qos and i reset router and re-configure from scrath  but nothing helps 

and another one is my negotation speed is 300mbps i also checked that one and another thing is also checked there are no devices and applications or downloading on my phone and laptop

i think the issue is present in firmware and not properly configured in 2.4ghz so i request you to provide beta firmware and i also suggest that release new firmware by reslove bugs in 2.4ghz network