Thiis is my personal opinion, but over the years I've been assisting with Gerber plots, the viewer which has had most instances in incorrect display is GerbV. They're usually pretty good about fixing these instances, but it's odd that this viewer seems so much more prone to errors than others.
A caveat. If you're looking for alternative viewers, it's best to trawl forums to find which are highly regarded. A small minority are fake, intended to plant trojans, so please be careful and research any new ones!