Season 2 is missing on Disney+ Germany and probably other European countries. They only have 4 seasons: 1, 3, 4, and 5. The only way to watch all seasons is to buy the DVDs on Amazon.
When I searched the web, people were reporting that it is missing since August and that Disney+ had a technical problem, but they have no information on how long it will take to fix it.
Have you heard something new?
season 02 is available in both English and German on Usenet, article ages are all around 5 months, so should be available for quite some time.