Other mistake: During an argument, Maggie's father mentions the border wall being built to keep people from entering the country illegally. This is obviously a reference to the real-life presidency of Donald Trump, but within the show's continuity, his comment doesn't make sense: in "Resist", the penultimate episode of season two, it's revealed that President Olivia Marsdin is literally an alien from outer space, and earlier in the season in "Welcome to Earth", she signed an executive order offering aliens such as herself full citizenship if they so desired it. If she's that tolerant of extraterrestrials, it seems unlikely that she'd be so intolerant of foreign immigrants as to resort to such an extreme action in foreign policy like building a wall on the border.
Other mistake: The title of the episode is about zombies in Venice, on TV everyone speaks of zombies in Venice, etcetera...but the news in passing show a map of Italy where the contagion zone covers large areas of the peninsula, such as an enormous region including the capital Rome and practically all of Northern Italy.
Die Glocke - S4-E6
Other mistake: When Jones is trying to convince Herr Waesch that she's the owner of the estate where his gala is being held, subtitles of his reply read "I personally procured this home. It's owners were French." The contraction "it's" should be the possessive "its."