Unfortunatly there are common misunderstandings in all religions. The problem is that in individual communities, customs and traditions develop that are contrary to the orthodox interpretation and tradition.
As an example, some Muslim communities are very anti-dog. The tradition derives from a story that one of Mohammed’s son in laws bodies was dug up and eaten by dogs.
I’ve heard Japanese Buddhists claim that if someone has an affair with a monk or nun, that for seven generations you will come back as ear wax. While it is truly believed by the unschooled in Japan, it is not an authentic Buddhist Belief.
I’ve heard Baptists from Texas, tell that when you pick up a Bible, you have to pick it up by the spine, and never wrap your hand around the pages, as it shuts out God from the Scriptures, and that is how Jesus picked up the Bible. (Funny as books did not exist in his day, and the Scriptures, Old Testament only where found on scrolls.)
So too there are many local legends that are believed to be Catholic that are the farthest thing from being Catholic. They are hard to root out, sometimes harmless, but usually not part of the Faith.