EDIT: This issue seems to be caused by the EditableImage & EditableMesh beta
Sometimes a mesh will not load in studio until the BasePart it is assigned to is updated - which often involves moving or scaling the object. The simplest instance of this happening is when you open a new file and set the Shape property of a newly inserted Part to another value. The mesh will not update in the viewport until I move the BasePart.
This also occurs for newly uploaded MeshPart meshes. If you insert a MeshPart and click on its MeshId property to upload a mesh, you will often notice a block mesh appearing instead - like in the video below. This can also be reproduced by opening a new file, inserting a MeshPart and uploading a mesh through its properties. Dragging on the MeshPart will cause the object to update and render its mesh properly.
Expected behavior
I expect my meshes to load immediately after setting the Shape property or after uploading them to a MeshPart.