Using another laptop as a second screen through wifi and its just really laggy. The fps inside the statistic tab only hover around 15 to 30 and video is unwatchable even tho i already switched to 60fps
Routers can cause lags and latency. Bypassing them always improves performance.
This does not only apply to USB Tethering, but also to direct ethernet cable connection and WiFi Direct connection.
Configure Windows Primary PC or Secondary Viewer Device as WiFi Access Point (Hotspot) and connect to it before connecting spacedesk. Please check chapter “Performance Tuning” in the instruction manual: https://spacedesk.net/user-manual