Hi. I just started to use Spacedesk to make my old phone as me secondary monitor. Mainly to use as sensor panel for my PC. What I notice is that when I played Borderlands 3, the monitor is still on but my sensor is not there. But what is more important is that there is a long(few minutes) of keyboard input lag. So, it is very annoying to play any games at all as it hinders with my character movement greatly.
Routers can cause lags and latency. Bypassing them always improves performance.
Configure your Windows PC or Android device as WiFi Access Point (Hotspot) and connect to it before connecting spacedesk.
USB Tethering and Android Debug Bridge cable connection can also achieve the same result.
Please check the “Performance Tuning” chapter in the user manual: https://spacedesk.net/user-manual