UV overlapping problem

I select all of a mesh and use the smart unwrap to apply the UV map to my mesh.

But when I do this, it almost always creates overlapping UV’s.

I go into UV editing and click “select overlap” to move the overlapping meshes to a different area of the texture, but it still results in overlapping textures.

How are faces overlapping themselves? How do I fix this?

Maybe you wanna re-unwrap with a larger island margin so the pieces have a greater gap?

Did you apply the scale to your object? ( Scale=1 ) Obviously before unwrapping.

There is no real reason you can’t separate the overlaps, as you have done, and move them ( to the right ) x > 1, so they are one section beyond the image texture, obviously easier when the texture map is square and just create a UDM tile. It is used in game engines all the time.
Or you could just select all and pack islands with appropriate padding.