> yes I pick my 2 points "directly" on the "up edges" of the box!

Ah, I see.

But this is a feature, not a bug! :)

Object snap takes priority over grid snap, so if you have object snap enabled and you move over an edge, you should see a bit of text "On". This is showing that the "On" object snap has found an edge to snap on.

If you don't want to snap on the edge and instead only the grid, you'll have to turn object snap off temporarily with the toggle at the bottom of the screen.

It kind of has to work this way, because if grid snap had priority you would only ever snap to the grid since there are usually so many grid points visible on the screen.

- Michael