Hi @saboreq,
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
Can you please send us the diagnostic logs of your primary machine while your spacedesk videowall setup and Nvidia surround are active?
Just open the spacedesk Driver Console -> Diagnostics, then click the “Save All Information” button.
PS: Saving all information will take a few seconds, then please send us the whole folder which contains all the diagnostic logs collected.
Please right-click the folder -> Send to -> Compressed (zipped) folder, then attach the *.zip file in your next reply.