Might want to provide a permalink.
House numbers should be put where you clicked the road.
IE: Click the road segment at th point where you would like to put the house number, then put the left and/or right house number respective to the side of the arrow drawn when clicking the update house number edit option.
Not, that house number for some reason need to be approved by an area manager. And I've seen sometimes when that happens the dot drifts off where it was originally placed. Might have to have some support insight on that part.
I'm hoping that the house number system gets some more love in the near future, as my opinion it's the one of the rougher areas of cartouche.