Right so, purchased this adapter and I think I made a mistake. Looking for a solution to improve my Wi-Fi download speed.

With official drivers from TP-Link website I'm able to download at ~20 Mb/s

With this driver https://community.tp-link.com/en/home/forum/topic/209500 I'm able to download at ~50 Mb/s

I tried checking speed by sitting next to the same table, with my laptop and couple phones. Download speed is 400 Mb/s

Did anyone actually found a solution for this slow wi-fi speed? Or should I just return it and get something better?

I'm using fibre internet with C7 Archer router.