It’s a rolling time period.
Essentially the way that it got explained to me is that:
- You essentially get 3 in a 24 hour period
- They “refresh” at a rate of 1 per 8 hours.
So think of it like your titan, raid or world energy flags… This is a “skip chest” flag. You have capacity to store 3x skips. Once you use the first one it starts regenerating it, taking 8 hours for it to fully regenerate.
If you run out of skips (i.e. get to 0 remaining) it has a timer until your next skip flag becomes available.
This timer will always be somewhere between 0hrs and 8hrs, as this is the time it takes a skip to regenerate.
Hope that makes sense?
It’s unfortunately not a bug and is designed to stop players taking advantage of the skip chest function to get unlimited elemental chests.