The server is running on Xubuntu 14.04 LTS (bare metal, not a VM) and is working nicely. Running the client on Android also seems to work and on my internal LAN the speed is impressive (watching a remote video with sound is no problem and hardly any lag). BUT, the Android system in question is an Android box (version 4.4.2), so no touchscreen and using a mouse is highly inadequate. For example, I can select a window, but not drag it or resize it.
We’re aware of issues related to hardware mouse, but the example you did sounds weird because interactions with windows should work correctly.
Can you please check if the option “Show the cursor pointer” in Input settings is enabled in your client? We’ve found a bad interaction between that option and the hardware mouse, so you need to disable it to work around the issue.
I can confirm this issue. There are Android devices that have no touch screen. For instance, the PC For TV devices have a mouse pointer, and no way to touch the screen with your fingers. The NoMachine client runs perfectly on these devices, but the mouse pointer does not work for dragging windows and you cannot expose the corner activation feature.