3D model help

Hello, I have the following problem... I want to adjust the print area on the cup from the shop. I tried to do this with Blender 6.1, and so far everything worked fine. However, the 3D model is not loaded in the configurator. I noticed that the file is also slightly smaller after export. For testing purposes, I imported the default file into Blender and then exported it again, with the same result: the 3D model is still not loaded. Does anyone have an idea what the problem might be?