Hi,

Please check if you are 2-3 meters away from the wifi adapter other than the wired adapter. TL-WPA4220 contains a wired adapter and wifi adapter. Wired one is used to connect to a router to transfer internet signal, wifi one is used for wireless clients to connect.

If it  is, how many signal bars do you have when you are 2-3 meters away from the wifi adapter? Except your laptop, do you have same issue on other devices like phone or table?

Please plug the wifi adapter to different locations and see if it is same.

Good day!

Yes it is the same in all devices (phones and laptops).

The connection has all bars but it disconnects a lot to no connection. So it's either all bars, or no connection.

When I try to move it even closer (say 500m) the same still happens.

Hi,

Please check the current firmware and hardware version, if it is not the latest one, please update it first. 

https://www.tp-link.com/us/support/download/tl-wpa4220kit/#Firmware 

How to update it: https://www.tp-link.com/us/support/faq/1614/

Then you can fix channel as channel 1, 6 or 11 and change channel width to 20MHz.

Any updates, please let us know.

Nice day.