average load of CPU gets with waves plugins

hi everybody,
i am trying some waves plugins (demo version) on my cubase 8 pro on a desktop pc with a scarlette focusrite 18 but the problem is that with just one track and only one waves plugin loaded, if i pass the mouse icon on every single parameters the audio drops out until i put it out from the plugin editor. it doesn t occur if i work in general editor mode. i’have tried to put on a lot of tracks with many plugins loaded, the audio is always good and the average load doesn’t pass the half, but when i just pass on the mouse in the editing image then it starts drop out. I can t imagine how to fix it. i thought my graphic device was the problem, is an intel integrated device, but it has 1760 mb of shared ram. what do you think is the cause of my drop out issues?
thanks

If it’s Waves that’s causing the issue then it would make more sense to contact their tech help team, as you’re a prospective customer you should get some help from them.