Blender isn't snapping to the grid, its shift 1 grid space away from the original I'm trying to make a few modular assets. To support my quest, I'm using grid snapping. However I have noticed that when moving faces or vertices, it doesn't snap them to the grid, it just moves them 1 grid space (based on the grid space I have set 0.5 in this case).
Here is an example:
I want to move this face onto a grid.

When I move it this happens. It just passed the grid.

How do I turn on absolute grid snapping?
Check the Absolute Grid Snap box in the snapping popover to enable absolute grid snapping: