Strange behavior when displaying 3D models

Hello!
I've been trying to add 3D models of some ships to a Cesium map. The original models are in Sketchup format (.skp), so I've converted them to Collada and then to GLTF to add them to the map.

Although I've been successful with the conversions and adding the models, when they are displayed on the map, for some reason, some lines appear out of place. Please take a look: http://thebob.com.br/maptest/cesium/apps/helloworld.html

This can be specially noticed on the third ship from the back, which displays a lot of misplaced lines to one side. Upon closer inspection, one can see that the lines are actually part of the model, but that for some reason got rotated at a wrong angle.

I've tried using different conversion options and tools - both the online and offline converters - and the result is always the same.

Any idea why this is happening, or something I can try?

Thanks in advance!

Oh, just for the record, the Collada format model seems to be totally fine, when opening it with Visual Studio, for example.

Hi Daniel, can you post the original dae models so we can check them out?