I imported a small plant fbx file that looks good in the Transmutr viewport but when exported to skp it is missing faces. I have tried making it much larger but the result is the same.
When converting it to skp with Simlab it works so most likely it’s a bug.
Also the Simlab file is much larger.
Here is a link to the files: https://white.egnyte.com/dl/UyHMv7ybWF