I have experienced the nearly same issue as Xilos. We used UVNC to do administrative tasks on some Windows-Clients. Now on Windows 10, everytime an UAC-Dialog appears, I am "kicked out of the session". I figured out, this only happens when the Query Windows is displayed. But this is a feature we would like to use
I can see that uvnc_service is running by "System".
I tried the latest UVNC Version in x64 and x86.
I tried to uncheck/check "Allow service to interact with desktop".
I tried to disable Windows Defender via Registry and made sure no other Anti-Virus solution is installed.
I could reproduce this problem on different devices, even on a new notebook with preinstalled windows 10 x64 Pro and on a PC with freshly set up Windows and other programs installed except Intel/Realtek Drivers and UVNC.