Merged 3MX productions do not work web ready on the cloud

I can merge 3MX productions as per the instructions here https://communities.bentley.com/products/3d_imaging_and_point_cloud_software/w/wiki/24605/merging-3mx-files

and the 3MX file opens fine in Context Capture Viewer, but when I also copy in the 'App' folder and upload to Azure, the model does not load. All my other models with a single 3MX production work fine on Azure, but not my merged one.

Any advice on why it is not working and how to make it work?

Thanks