Once again I find myself in Blender 2.82 limbo.
I have imported some objects from a .obj file.
In the model window I LMB on an imported object. It shows no indication it is selected in the window. The bar in the tree moves.
If I LMB on a cube I added it seems to stay selected, even though the bar in the tree has move to some other object.
If I tab, the selected object is in edit mode and I can select and modify.
(So, I guess the question why is there no indication of selection when not in edit mode?)
(I was actually pretty good with Blender several years ago…after disuse for years I just am having trouble with 2.82 UI changes 
)