When Vivian and her German translator Mira track down Anna's family villa, right before they discover it, the street and parked cars change mid-sentence.
When Vivian receives the letter from Vadim, it states his address as "Kammergasse 14, 54329 Düren / Eschweiler".
However, earlier when she is invited into the Sorokin's home, the house number is shown as 16. In addition, the ZIP code is wrong, it's in a completely different state and the town of Düren is next to Eschweiler, but has nothing to do with it. Mail isn't routed through there for Eschweiler and they are in separate districts.
Vivian's trip to Germany appears to take place in the middle of winter, including several snowstorms shown onscreen. The timing of the trip is approximately three months after Vivian gives birth to her daughter and publishes her Manhattan magazine article, at the end of February 2018, meaning that her trip had to have taken place in late spring, when Germany is long past its winter weather season.
Incorrectly regarded as a goof.
A mother who is currently breastfeeding would need to pump while she was away from her baby because her body would continue to make breast milk even if she wasn't feeding her baby and she may have had to pump and dump it. It would be extremely painful and she would be become engorged if she didn't do this. This is probably why she was leaking milk through her shirt when she went to Anna's parents house. She would also probably want to continue pumping so that her milk would not dry up and she could continue to breastfeed when she returned home.
When Vivian is interviewing Anna's father the translator only translates his German to English and never Vivian's English into German for him to understand.
Anna says she use to read "Vogue Deutsch". That one's actually named "Vogue Germany".
On the train, an attendant shouts to announce that Eschweiler station is next. German passenger trains are equipped with loudspeakers and prerecorded announcements that can be heard in the entire train, much unlike one person shouting in one of the wagons.
In the early 2000s, as a rule, regular German high schools did not have a cafeteria because no food was ever served there because school used to let out at noon. Pupils were expected to go home, be fed by their parents and do lots of homework. Political efforts at extending the school day were only just slowly getting under way when Anna Sorokin was a teenager. The entire cafeteria scene with the snickering clique of hostile girls seems transposed from American high school clichés that don't really apply.
Vivian travels to Eschweiler on a train that bears the livery and logo of Niederbarnimer Eisenbahn (NEB) - a train company that operates regional services on lines to the north and east of Berlin. Eschweiler is west of Berlin, over 600 kilometers away and thus best reached via long distance services.
The train that Vivian is taking to Anna's youth hometown of Eschweiler, while looking like a typical German regional train, does not actually go there. It's clearly labeled "Oderlandbahn", which is a rail service from Berlin to the Polish border which is at the opposite end of Germany. Eschweiler is located in the west, close to the borders to Netherlands and Belgium.
Vivian reads her article from her hospital bed after giving birth. But when she went into labor, the article still needed to be fact checked. It's virtually impossible the magazine would've been able to fact check her article and print and distribute it within the day or two she would've been in the hospital postpartum.
Anna pays the cab driver a $100 bill. But the cash in her bag comes from the withdrawal she previously made in New York, which she requested in $50 and $20 denominations.
Anna pronounces Eschweiler as an American would, not the German way that she would naturally use.