When I create a new scan, then go throigh the step, fusion, mesh, merge and generate model and finally I can export as an STL including the other formats. Save the project and close the project. When I re open the same project or any other project the merged model mesh is missing even though I have the meged meshes as you can see in the image. It seems the final merged mesh isn’t saved when I save the project.
Merge only uses point cloud data and not mesh data. So meshing the scans before merging is a wasted step. After the merge then you can do some additional cleanup like overlapping points and then perform the mesh step.
You never generated a mesh from the merged point cloud so there is nothing to be saved , please fuse the scans , clean them up, merge then clean up again from overlapping points and lose points then merge and save it .
Next time you open your project you will have merged mesh .
The Merge tab don’t use meshes models for merging only point clouds, that why you get a point cloud as a result and not mesh .