I have had an ongoing issue with UnityEvent properties capturing all drop items in the inspector. Here is a quick video demonstrating the problem: There is no custom inspector being used. I just updated to 2021.3.26f1 to see if this has been fixed. It hasn't. I did have Odin installed, but I removed this in case it was the problem. It wasn't. I don't have any other packages installed that might cause this behaviour.