Performance on wireless networks can be improved by configuring the Windows 10 PC/laptop or the mobile device as Wifi Hotspot / Wifi Access Point. Connection to this Access Point needs to be established before connecting spacedesk.
To configure the Mobile Hotspot option on Windows 10 PC/laptop. Just go to Start → Settings → Network & Internet → Mobile Hotspot, then turn it ON. Try to connect the client device(phone/tablet/laptop) to the wireless network name generated by the Mobile Hotspot. Then run the spacedesk VIEWER and connect to the IP address of server machine, in this case it should be the IP address of the Mobile Hotspot network generated (Microsoft Wi-Fi Direct Virtual Adapter).