Problems with black areas on the model UE5 (4-26)

Hello all. I have a problem with a scan from sketchfab: black areas appear on the model (see photo). I have checked the face orentation, but in blender these areas are displayed as light blue. what could be the reason for this? And how can I solve the problem?

Do the holes still appear with a white material assigned, or perhaps in Unlit view?

Yes. I think it has something to do with the face orientation. in blender, these parts are shown in a light blue instead full blue.