Deleted Structs+Enums slow down first start / opening of BP

After I edited and deleted some of the structs and enums I have made for my game, I’ve noticed a significant slowdown in the editor when I’m trying to open first Blueprint or use the Play in Editor function.

It takes up to 90 seconds to open the first Blueprint or first Play in Editor, after that, the editor runs fine without any slowdowns.

I guess these changes of structs and enums are somehow still somewhere in the files of the project, slowing down the initialization / first launch every time I open the editor.

I’ve already deleted my Intermediate folder, but this issue still persists. Does anyone know what could cause this slowdown and how to get rid of it?