@TheGreg23 

Hi, without mesh technology on the TL-WPA4220 and your router, the roaming actions are totally decided by your wireless client devices, and when you move from one adapter to the other or to the router, if previous WiFi signal is still working, the client device might still stay connected to previous WiFi because the signal strength etc. might not reach the roaming threshold of the client device.

You may try to set up the same wireless network name and password for all the adapters and our router to see if the roaming experience will be improved.