‘The Boy from Medellin’: The J Balvin doc doesn’t hit the right notes

“The Boy from Medellin” – Medellin is the capital city of Colombia’s Antioquia province.  It has a population of just over 2.5 million, and one of its favorite sons filmed his documentary here.  International reggaetón megastar J Balvin makes a triumphant return home to put on a massive show, but then again, “the best-laid plans of mice and men often go awry.” Director Matthew Heineman follows this chart-busting marvel to his hometown for one week leading up to the planned live spectacular, but a set of soccer-stadium-sized stumbling blocks place…