Guild Wars 2

So I did the event to get the invisible mushroom spore, because I wanted to get it for my engineer’s weapon, for this you need nuhoch stealth detection to kill a REALLY tanky mushroom that is in the middle of a ton of mordrem including 2 vets. Nevertheless, I completed the event and got the mushroom spore…and it counted toward berserker specialization collection and nothing else?

I did it on my engineer just in case it only counted for one, which I wasn’t too sad that it only counted for one spec, but for it to not count towards the character I did it on? This to me just seems really stupid that I have to do it countless times on different characters hoping for the rng to love me and give it to the right specialization.

p.s. I did it again on my engi and didn’t get the spore from completing it again on the same character so it’s either once per day per character/account or once per character per account.