Yup. If you use debuffs, you're on a timer to get shit done.
Buffs, on the other hand, don't care about timers. Assuming you're not under a raid time limit (generally one hour), you can even come back after a day. Or two. Or a week.I think that's just a display bug. It goes away, but the game doesn't refresh until you do something. It's still gone and won't be counted for even when you do something while it is visible on your screen.
Paralyze is a pretty good way to notice this in action.