HELP Maya Mesh Import Problem


First of all i was making a Cruise Ship in Maya, everything looks fine inside of maya,
I used the “Difference Tool” to create some windows inside of my cruise ship, again ,
everything looks fine inside of maya, the outside looks good and so do the inside of the ship where i made the windows.
Somehow when i import it in UE4-18-2 to test it how it looks,
the windows looks fine on the outside of the ship, but the inside looks all broken and you can see trough on parts you shouldn’t.

Look at the screenshot below :

How do i fix it?
Is it something i have to check/uncheck when i import it or do i need to do something else in maya for it to look like it should?