Edit: Ok so it has been fixed by RJG, thanks to him, I had the same shortcut for select vertices and select gizmo, which seems the case by default? and I had to came back to right click for selecting vertices, which is perfectly fine to me.
I meet this very bad problem with 2.8. when the gizmo is displayed.
In Object mode it causes less problems, but when I switch to Edit mode and try to select a vertex close or even not so close to the gizmo, as if it seems like it's the same shortcut, Blender thinks I want to select and move the gizmo instead of the vertex, as if the gizmo was on a layer over the mesh, and not the opposite, which messes up a lot the work with the mesh, it makes you often move inadvertently some vertices.
In 2.7 it didn't work that way, because it was not the same keying for selecting vertex and selecting gizmo.
This doesn't seem logic nor convenient at all to me, it's even very bad :/ Am I missing something like an option to activate?
In advance thanks for your answers...