has the handle been uploaded recently? Items that haven’t gone through the asset moderation check will appear as invisible to anyone but the person who uploaded it by default as a safety measure. If not, make sure that the part is welded/anchored properly as parts can be moved around
If you just recently uploaded the mesh then thats normal because it will take some time for the mesh to be uploaded and pass moderation so other clients can actually download it.
This should usually be over in no more than 30-45 minutes, usually its way faster.
The same issue happens with decals, textures, sounds, etc.