Blue Buff Bugged

I didn't get the chance to record it in game, but its happened to me more than 3 times now. Blue buff will randomly stop spawning on purple side, and the icon in the jungle will stay up. So it looks like blue buff is up but it will not spawn any longer, this happens mostly when we're behind in a game, making it that much harder to come back, even if it isn't a huge deal. I don't know what this is but if it happens again I'll be sure to get a recording of it and share it in this thread.