If I go to NEXT well at least last night when I was working on this it would cut all the way to the far side of the radius mounting bolt flange.
Are you sure you didn't have Through All selected? I think the reason To Next doesn't seem to work is because you have the sketch on a plane that is offset from the surface and it is cutting To the Next surface which happens to be the one you should have the sketch on.
If you place the sketch on the side face of the housing then To Next will cut to the next feature/surface. If you could create the mounting bolt boss after the current extrude cut you may have better results since Alibre may have an issue ending a cut on the curved surfaces or it may go thru them.
I modified your sketch to remove the slope then used the To Geometry type and selected the opposite face. After the cut I used a Chamfer to remove the step and create the slope. In order to get accurate values for the chamfer I set the decimal display to six places then measured the feature for values to enter into the chamfer tool.
As an alternate, if you have the Direct Edit tools you can cut Through All then use the Remove Face tool to remove the top face of the cut that extends thru the far side boss.
One final note, add your Alibre version to your signature or at least mention it when posting so we know how to answer and you won't get suggestions that your version is not capable of performing.