Move tool only moving one face, and detaches it?

Hello, I really hope this is a simple fix that Im just missing because I’ve been searching around and can’t find any answers.

My issue: When I try to use the move tool, it only moves one specific face and detaches it from the rest of the mesh. This does however only happens on a mesh that I imported from Blender (a .glb if that matters), where the move tool works fine on in-app meshes.

Attaching video of the issue

Update- the mesh also breaks apart when I use smooth, is this an issue with the import? How do I fix this?

What happens when you seperate your mesh (scene menu … ) ?

I guess your mesh is not connected.

When I separate my mesh, it puts every individual face on another layer.

How would I go about fixing this/ reconnecting the mesh so that I can sculpt?

Thanks!

Maybe this helps: