What were the major political upheavals in Germany during WWI?
There were some upheavals in Germany as the war went on, with the upheavals becoming particularly intense and disruptive in 1918.
During the war, Germans suffered more than people from nations like France and England because they had much less in the way of food and other consumer goods. This was largely because Germany imported many of the things it needed and was cut off from its suppliers by the Royal Navy. Because of this, there were strikes in which people demanded more food as early as 1917.
During 1918, things became much worse. There were more strikes and even marches demanding an end to the war. Most importantly, the German navy staged a mutiny when it was ordered to go out to fight the British navy at a time when it was clear that the war was already lost. This mutiny ended up toppling the monarchy and helping to lead to the end of the war.