Throught the movie Goebbels is walking normally. The real Joseph Goebbels had a clubfoot since he was 4.
The first meeting between Goebbels and Günther Quandt was in 1931, shortly before his marriage to Quandts ex-wife Magda. It did not happen in 1925, as depicted in the movie.
Goebbels met Magda Quandt in 1930 in the offices of the Nazi party, years after her divorce from Günther Quandt. It didn't happen at their home in 1925.
Towards the end, the train to Switzerland is clearly a British Great Western Railway one.