Will connecting the Success pin form the “add to stack” node to the success pin on the “output” node make a difference?
I can’t seem to find anything wrong with that blueprint without seeing all the rest of the code associated with it.
That being said.
Error and bug hunting is an essential skill that will help you out in most situations in UE4. Try adding a “Print String” node directly after each branch, True or false check, any choice or Success/Fail check involving the “Pickup Code”. Be precise in the text on the “Print String”. You should be able to use that information to find out exactly where your code is failing. If that doesn’t narrow it down enough to solve the bug you could try adding some “Is Valid” checks on the variables involved when they are called to see if there is valid information being transferred and accessed. Once you narrow down the problem some I might be able to help more.
There are also some very helpful videos and tutorials out there on bug and error tracking that people with more experience then me have posted. Search “UE4 Find bugs” , “UE4 Bug Tracking” or something similar on Youtube or whatever search engine you use.