I'd be interested in the steps to reproduce. Did you mate the 3D Label as well? If so, with the model?
It would be great if you could share a screenshot of it looks like and how it should look like - just to get an idea where the misplacement happens.
I've tried to reproduce the behavior with some standard elements, but the Thingmark will stay in place (at least with my test scenario).
Thanks for trying to repeat. I did not mate the 3D label to the model.
Unfortunately, I'm not able to repeat the issue where the position of the thingmark on the canvas doesn't match the position in Preview or my thingworx view app anymore. I've seemed to be able to move past the issue. If it happens again, I'll take pictures of my canvas and preview to paste here.
I'm probably asking too much of the software at this time. I'm also wanting the mate condition to hold it's constraint to the surface a little better. If I mate the thingmark to the model and then translate or modify the scale the model, the thingmark doesn't stick to the surface. I'm sure this is intended functionality at this time...but something in the future for a nice to have.