Still problems here. Occasionally it does work and I'm not sure why leaving it for a day should have any effect but I've found.
In the evening
1st time I go to it, it works.
2nd time, black screen, but if I search in the V6 menu and go to a prime program directly it works.
3rd time.... nothing works including rebooting etc.
Also it must be related to a reasonably recent change as I was using prime a lot without any problems until the start of this week.