@Tony No, I did not try that. Why the described issue happens with tpPLC utility not with Netgear's Genie utility ? Both PLC devices TL-PA4060v3 and XAV1601v2 are connected the same way to the router...

I installed a powerline home network consisting of three Netgear XAV1601v2 devices and two TP-Link TL-PA4010 devices connecting one of Netgear's to port LAN1 and TL-PA4010 to port LAN2 of my router....