Hey Mate,

If only wireless speed is slow, you can try to change some settings, such as change the channel and channel width.

If it's still not good, you can try to follow the following FAQ for some troubleshooting:

https://www.tp-link.com/en/faq-2170.html

Hope it can help  you.

if you disable wmm, then the wifi shall only 11g, maybe your client device is forced not to work on it.

as for the bad wireless, you could fix the channel to work on 149~165, at least it works for me.

the speed could reach to 140Mbps when I close to the router, by the way, my ISP give me 150M

vivek23 wrote

With LAN I got 90 Mbps download speed through my FTTH connection, but on wifi it comes down merely to 40 mbps maximum on 5Ghz and even lesser on 2.4 Ghz. When I tried to disable WMM service internet connnected was showing but it stopped working ( no site opened) and when I enable again internet start working.

Why so less wifi speed, is the hardware faulty ?

I'm using wifi near the router.