I'm late to this party, but this thread saved me so much headache (thanks a ton!).
If anyone stumbles on this thread in the future, and you never had "Background Application Max Frame Rate" enabled, make sure to check the other "Max Frame Rate" value to sanity check the same. It seems if you use either one of these options, it can lead to the same result.
I am SO glad this issue is fixed. It was driving me nuts!
