Thnx everyone,
From monitor Nr1 fullscreen jumps to monitor Nr2 and it's not possible to move it to monitor Nr1.
I totally forgot to add one of the steps (#3) Sorry about that!
1. In preferences select "all" on the lower left hand side.
2. Expand the "Video" settings on the left hand side (click on the "+" box next to "Video")
3. ---> Expand the "Output modules" settings (click on the "+" box) <---
4. click on "DirectX"
5. Check the box marked "Use hardware YUV->RGB conversions"
6. Select the display you wish to use from the drop down menu (across from "Name of desired display device").
7. Save your settings.
I had the same problem until I did the above. Yes it is a bug. A bug that can be overcome if the above fix. Again I'm sorry I left out the step required to get you where you needed to go.
When you are at step 6 it should look like this:
Notice the expanded video and output modules menu, with "Name of desired display device" drop down menu selections.
Please try the above steps again. Good luck!