WiFi clients to TL-WPA4420 v4 with firmware 4.0.4 Build 20210222 Rel.42127 either are losing connection or cannot register to it (there is no IPv4 address assignment). The adapter is on a powerline network with a TL-PA4010PKIT v4 with a 190820 firmware. The home router is a Fritz!Box 7590 and no other router (and thus DHCP, DNS etc. server) is used.

The problem seems to be only related to Wifi clients and not Ethernet ones and when it's occurring, both the clients cannot connect to the adapter and the adapter "disappears" from the network (it's assigned IP is not responding). Tried both dynamic and static (always within the router's network) IP settings. Also, both a separate WiFi network and a router clone one are experiencing the same problem.

There's no indication that a DHCP server starts at the adapter's log.

Please advise.