We always test it with cable connection and have one 1 Gb switch (not router) between spacedesk server.
We are not using MS store version of client as it seems have older version than that installable package from your site. Now we go away from that windows client as we need 8 display connected and there is no possibility to have more clients on one computer and have used all nvidia hdmi output in use.
Now we are focusing mainly to setup it on some android tv boxes. Our today test will be on