Mildoo
Let me just copy and paste my entire spoiler for you
emotion_eyebrow
You can not donate the entire bundle.
You have to unpack them first and do it individually.
When you donate an item there are 3 tabs at the top.
Equip, Special, House.
Click Special when donating the Caches or Grab Bags.
You also may need to wait a few minutes for your inventory to refresh.
See I did all that. I even logged out, closed my window and cleared my cookies and history. Then came and logged back in. They are in my inventory but not there when I go to the event page. Maybe it's just messing up. I don't know. If it's working for others great. Maybe it will work eventually.