At the World Championships Seitz competed all four events during qualification and helped Germany place ninth as a team. Although they did not qualify to the team final, they qualified a team to the 2020 Olympics Games in Tokyo. Individually Seitz qualified to the all-around and uneven bars finals. During the all-around final Seitz finished in sixth place and became the highest placing German female gymnast at a World Championships all-around final since Germany's reunification. Additionally she received the second highest uneven bars score of the day behind reigning World Uneven Bar Champion Nina Derwael of Belgium. During the uneven bars final Seitz fell off the apparatus and finished in eighth place.