UI frame delay

[ZOulhadj]

At the moment there is a latency issue when rendering the UI. All UI elements are sluggish and trail quite some distance behind the mouse cursor. Additionally, since the viewport is being displayed as a UI element this also leads to slow camera controls.

Upon further testing, launching the application in fullscreen mode the first time solves this issue. However, alt-tabbing out and then back into the application causes the issue to arise again.