Had this problem when I last played the game, a few years ago, came back the other day and it's still a problem. Can't be hardware related since this is an entirely new pc. To be clear this was not always a problem, it started after one of the big updates( can't remember which one ). Also of I play the game in windowed mode the loading screens work fine. Tried searching Google and found various part related to the issue from different years, but no solution.
The load screens don't work, and for me and a few other PC users I know, it will randomly minimize when running in full screen (which is not-awesome during an elite raid). This also does not happen in windowed mode.