I believe that it’s what is preventing spacedesk on the tablet seeing the spacedesk client on the laptop. It just ‘doesn’t work’.
Just to be on the safe side. The android device (client app) should see the „server“ (WIN10 driver software) not the client software. I guess you installed it correctly since Wifi is working.
In this post I mentioned my setup and connection process for USB tethering.
If you allowed the installer to adjust the firewall and add spacedesk, it should work.