Lines become pixelated

Hi all,

I’ve been using TBS since V05 and I’m experiencing display problems for the first time.
Whenever I switch workspace (from Scene planning to Drawing or vice versa) the lines are displayed pixelated.

My PC’s specs should be more than enough:
Intel Core i7-5960X CPU @ 3.00GHZ
GeForce GTX 780

The project is very simple, not even coloured in yet.
All drivers and software are up to date.

I’ve tried about everything in the display settings,
and the lines look good on startup, but as soon as I change workspaces, it’s pixelated.

Any ideas?