If you buy multiple Witches Grab Bags from the Impressario, some of them will disappear on use without rewarding you anything.
It seems, there is a mechanic to prevent user from receiving the reward from the bag he already owns. So, I assume, if you bought two bags with two similar rewards, the second one would be nullified after you received the reward and the bag would just disappear on use.
P.S. Couldn't find a dedicated topic on Witches Festival bugs, so I am not sure whether I should create this topic or a bug ticket.
Edited by NoTimeToWait on August 4, 2020 6:38PM