In order for me to create some repro steps, can you post a chunk of the code that is causing the issue? This would include the function declaration (as you have in the screenshot). All of the argument types of the function (US_SUBCLASS_CHARACTER_VOLATILE and FE_ITEM_FOUND_TYPE). And, the function itself.
If this is not possible, can you create a small project that displays the same behavior that I can download?
Thanks.