I purchased a TL-WPA4220 which was was unreliable. The connection did not stay up more than a day or so.
The device came with
Firmware version: 4.0.3 Build 20190326 Rel.43406
Hardware version: TL-WPA4220 v4.0
After a bit of browsing I found this https://community.tp-link.com/en/home/forum/topic/78910. Adding the following script on the Ubuntu Linux machine at the other end of the powerline adaptor solved the problem and it has been up for a week now.
while true do ping -c 1 192.168.0.1 sleep 60 done
Actually it still isn’t very good, stays up about a week and then needs to be powered off. I downloaded the tpPLC app for MacOS and under the advanced setting “Mode” menu, unset the “Power Saving Mode”. We’ll see if that fixes the problem.
I also found this link https://github.com/qca/open-plc-utils which I should explore later.