I design my models with Sketchup and convert them using ModelConverterX. I’ve been having this issue for a while now and running out of options for what I can do about it.
In the game it looks faulty like this:
In Sketchup and MCX it looks like it should:
So far I found out it happens when there is a line from another item in the model touching the face.
I also include the models and textures, so someone more knowledgeable than me can investigate if he wants:
I’m a bit sad that it keeps on failing in MSFS. I successfully made games for other games (FS2004, RCT3, No Limits 2) which had easier and harder import procedures. (No Limits 2 was heaven, it straight up accepted .skp files; RCT3 was the opposite and required a lot of steps )