Critical wifi roaming (MAC learning?) regression in TL-WPA4220(EU)_V4_22040. Stick to 2019 version
There is a critical regression in wpa4220v4_eu-up-ver4-0-4-P1-20220408-rel36351-APPLC.bin, don't use it. It took me many hours of testing to isolate.
Workaround: stick to wpa4220v4_eu-up-ver4-0-3-P1-20190326-rel43406-APPLC.bin instead. You will lose the interesting new feature "DHCP server: No" but at least the most basic features will work.
The issue happens when you "roam" from one Wifi Access Point to the WPA4220 v4 wifi. Then the MAC address learning seems broken: using wireshark you can see that all traffic is flows normally to you through the WPA4220 except traffic to your device! After a 5 minutes downtime packets to your device finally make it through the WPA4220.
Roaming from the WPA4220 to another Wifi Access Point is not a problem, roaming is broken only one way.
Strangely, wired Ethernet is not affected. If you unplug the cable from another switch and to the WPA4220 then there is no downtime.