It looks like you're new here. If you want to get involved, click one of these buttons!
See attached image (as example) - How do I stitch faces together to get 1 mesh entity?
In the attached example all the triangles are independent faces...
If you have 3D Faces, you have to convert them to Regions first.
(Select - Create Region)
Then you can stitch them and will get a Solid
(if it was a proper Volume)
or a Surface.
Which you should be able to convert/degrade to a Mesh, if needed.
Convert to Regions - then DMSTITCH did the ‘trick’…
Saved as a surface.