I have the exact same problem. VERY frustrating. Have you had any luck finding a resolution to the issue?
BTW, while not a fix, you don't need to reboot, but only have to logout then re-login. Should be a bit quicker.
It amazes me that this isn't well documented with a fix somewhere. I just keep finding responses about adjusting your screen size resolution, or updating drivers
If I find a fix I'd be happy to let you know, but if you come across one, please let me know as well.