Actor collision capsule shape allows looking through some walls

With a capsule shape I can get this close to this wall, putting me inside the nonsolid support geometry with no "wall" behind it: https://i.imgur.com/oHBdE5x.png

With a cylinder I can only get this close: https://i.imgur.com/AyqAuAK.png

(RM-4447 from redmine: created on 2018-06-09 by Alexander Nadeau, )