I've experienced this with many different parts imported from many different sources. For example, I've downloaded a number of STEP files from 80/20's online catalog of fittings. Each time, I convert these STEP files to Solidworks parts. I use the automatic feature recognition, which usually works. However, once that new part is incorporated into an assembly, the mates initially work just fine -- until I close and re-open the file. Then all of the mates fail at once. I have read somewhere that this may be due to the Surface/Face ID changing, but I have gone through and manually given each face a unique ID, and it still breaks.
I have also verified that my converted SolidWorks part files are fully defined.
Is anyone else experiencing this behavior with imported STEP files?
Nice find!
Just curious, why do you need to perform feature recognition for vendor parts?