Sprint cancels when facing exact NSEW directions

I sometimes turn to go straight down, say, a corridor and find that I CAN'T sprint, and if I'm already sprinting during the turn, it gets canceled without me bumping into anything, and it only happens when my facing is exactly North, South, East, or West. IT EVEN HAPPENS WHEN I'M IN CREATIVE MODE, but does not affect flight or swimming. (while testing to make sure it's happening in creative mode, it cancels at 90 (West) and 180/-180 (North) , but not 0 (South) or -90 (East) )