You will receive approximately 20% of the XP that would be necessary for the level each collection is intended for, as well as another 20% for completion of the entire zone. Some collections also come attached with items and titles!
I totally understand how frustrating it is to have the items slip right through your fingers and disappear into nothingness right when you think you've got it. This is the most critical issue for Collections, and we're working to get to the root of what's causing this bug ASAP.
This was an error with the focus. It will be fixed in a future patch.
<@Elidroth> Paralytic Spores is on my list to fix already
Yes, the charm is broken. It was looking at quests unstead [sic] of faction. It will be fixed next patch.