It's possible your computer's specs are too low to handle the heavier OS and the cintiq at the same time?
I am no expert but I have noticed that video is very laggy for me when I use my cintiq with my new laptop (Windows 10, i5 processor, 8GB RAM) but it isn't when I use it on my old laptop (Windows 7, i5 processor, 16GB RAM)
Now whether that be because of the OS, or the lower RAM, or a combo of both I do not know.
My guess is that it's the specs because I know that when my old computer was at 4 GB RAM it struggled to handle the cintiq at all.