Gangplank barrel linking inconsistent over certain terrain

When linking barrels over terrain, successful links seems to be pretty hit-or-miss depending on the location. Some walls always work, some walls sometimes work, and some walls never work. Some walls even work in certain directions but not in others (see example photos). These are not all of the bugged areas (inside red buff over to the back brush doesn't work either), but they some of the most important ones that have significantly affected my games on a regular basis.

EXAMPLES: (1st and last are same wall, but show's with a bit more clarity, this wall is one of the most important)