Shape fill doesn't line up with it's bounds... Watch please to understand

This is a very old problem that I have and I've been working this way in spite of it, anyways, I can't say it is always, it only happens sometimes (not rare not always).

Look at this, when I'm working with the "Snap to Grid" option on, sometimes this weird stuff happens. The outline bounds snap to my grid, but the fill of the shape doesn't have sense, what is happening here?

In occasions I have this. The "A" fill is aligned correctly with it's outline, but not the "R" nor the "M"

What do you think about this? Have you ever experienced the same? P.s: I don't remember my preferences of that specific grid I used in that work, is it necessary for you to know?