So I play a game, rank up, but then when I get back to the lobby I notice that my rank didn't stay. So far I've only noticed it when I get a high XP count, but that may just be because that's when there's the greatest opportunity to notice it. This has happened to me several times on my trek to 20/80. However, I have only noticed one or two instances per prestige.
Right now I'm working my way through 20th and as such I'm paying more attention to my number. I've been dropped back 3 times in the last 5 games and it's really frustrating. All those challenges and more annoyingly all of that double XP time has been robbed.