Snow is shown several times in Germany in the summer as WWI brews (after Archduke Ferdinand's assassination on June 28th, 1914). And as Freundlich's expedition enters Russia (on August 1) and Crimea by train, heavy snowpack is seen, remaining through the arrival of a total solar eclipse on August 21. This is much too early for this much snowfall.
The wrong seasonal setting isn't the only error in Chapter Six: In one scene, the astronomer sent to observe the eclipse is shown watching the eclipse from his jail cell. The sun (and moon) are shown near the horizon, but total solar eclipses only occur at around solar noon. Based on the latitude and date, the angle of the noon sun would have been at about 57 degrees, but the eclipsed sun shown is at less than half of that, barely clearing the distant mountain range.
Freundlich's expedition is shown crossing into Russia territory on August 1, 1914, on their way to measure the gravitational deflection of starlight during a solar eclipse in Crimea. But when Einstein is subsequently shown asking Mileva about an expected telegram confirming their arrival, she had already left Albert and returned to Zurich (July 29).