Loose door glass Options

[dgbldr]

I can't figure out what's wrong with my drivers door glass.

With the window up, it's pretty tight and everything lines up perfect. But with the window all the way down in the door, the glass is loose. Has about half inch play side to side. You can put your finger on the top edge and rock it. And it sits away from the outside weather seal. When you slam the door with the window down, it rattles.

In my other door, the glass tucks tight under the outside weather seal when it's down. And it's tight at all positions.

All accessible bolts and nuts I tried are tight. Does anyone know what this could be? Does anyone have a good picture of the regulator, glass channels and other stuff inside the door so I can get an idea what to look for? I know nobody ever touched this, so it must be something worn, loose or broken.

Wood appreciate any help.