Oh yeah, my german origins, I kinda had in mind that "pulver" is english as well, but thinking about it of course I meant powder. Sorry for the confusion.
Currently I store them "long-term" flat in a drawer (more compact) and "short term" standing, but as all of the bags were flat lying in the carton box the powder distributed in the whole bag and all of the ones I have opened yet had this problem (in contrast to the old zip-locked ones which where by the way in the same box).
The Huel zip lock needs a little bit more "pressing-strength" than the queal zip-lock, but it doesn't feel bad as, as they have a "defined" (feelable) closed state in comparison to the queal zip-lock which in my experience don't always seal completely.