Users with multiple 4K monitors connected may experience slowdown or sluggishness, especially if Virtual Set Editor is launched.
We have found that having one or two of those monitors set to a 60Hz refresh rate can contribute to this. Both of these monitors need to be running at 30Hz to perform well in 4K (3840x2160) mode.
To do this, exit to Windows, then right-click on an empty area of the desktop and select "Display settings".
Scroll down to "Multiple displays", and click on "Advanced display settings"
Select each 4K display in the dropdown, and check that "Refresh rate" is set to 30Hz.
After these steps, you may need to close and restart any NewTek software that you had open, or restart the computer.