I have had this problem for a long time now. On almost all atomic data types - from uint32 to in8, creating a function with those inputs or return types will always cause the editor to show them as bad_type (or, if they are within a struct, they won’t show up at all).
It’s not bug, rether design limitation, official statement from epic is reflation system does not support all int types for simplification reasons
Use int32 for any blueprint interactions