Brazil is always misrepresented everywhere, but two funny cases come to mind:

There was a House episode where Dr. House was treating a CIA officer who had been to Bolivia and had eaten a lot of nuts. At the end of the episode House realized the officer has actually been to Brazil and not Bolivia and then figures out that he ate Brazil Nuts, which could cause all the symptoms he had. In reality Brazil Nuts are much more common in Bolivia than they are in Brazil (or anywhere else).

The other case was Westworld, Vincent Cassel speaks perfect Portuguese while playing an American character, talking to a Brazilian character whose actor speaks it incorrectly and with an extremely loaded accent.