Issues with interfaces

Hi,

On my actual project i created an interface in blueprint, that only have a single function in it.
Then i created 3 abstracted class that implement this interface and each of those abstracted classes have a few children.

My issue is that i want to override the interface function in each of my abstrated classes but it don’t show in the blueprint menu. It does show in the function menu of the children.
I tried turning back the abstracted classes to normal classes and it don’t seem to change anything.

So what am i doing wrong? Are interface only possible to override if the are inherited interfaces (that sound very wrong), or i can’t do it on abstracted (that seem a bit weird to).
I’m really blocked here i don’t know if it’s a bug or something but all my project is about having abstracted classes implementing interfaces. So if it don’t work i’m a bit screwed.

Thank you.