Hey, I am having the same issues after 8.2.5. Loading screen seems to be changing gamma brightness to dim and bright back and forth.
There is another thread where many users are reporting the same thing
I have another computer with different specs at home where the brightness flickering during loading is not happening. My guess is something got messed up during the patch for some users. I hope they fix it soon; it is very distracting and disruptive.