First off, welcome!
I haven’t had a chance to dig into the .zpp, but my first guess is that there might be multiple rotation animations happening simultaniously.
The Earth itself might be rotating in Zappar’s example video in one direction, while the 3d model animation plays, rotating the clouds in the other direction, making it look like they’re standing still. For example, the clouds might be on a loop to rotate 360 degrees, while the Earth node is set on a different loop to rotate -360 degrees. I’ve done similar trickery to make a ferris wheel spin while the seats stay upright.
If there’s one thing I’ve learned over the last nine or so months I’ve been using Studio, it’s that a lot of trickery can happen within it to achieve the look you’re going for. Don’t be afraid to mess around with folder/group properties, or nesting subsymbols within projects to access different sets of properties as well.
As always, I usually drop links to some helpful pages within the ZapWorks documentation, so if you haven’t read them yet, you may find them helpful: