Missing face when exporting from Maya

Hi, I was having a problem when I exported the model from Maya and imported into Unity.
Three of the faces are missing.


When I changed the normals option from import to calculate, two of the missing faces disappeared but one still existed


Models in Maya looks good, even I tried to reverse the normal direction, or turn on the back culling mode the problem couldn't be fixed.


Does anybody know how to deal with this bug? Thank you!

 

Did you figure out how to solve this?