On the period WWII German photos from the personal archives of German soldiers, you can often see that many of the Wehrmacht soldiers wear not statutory boots, but various kinds of light slippers and half-boots. It is understandable, the soldier was not always at the frontline, often the units were taken to the rear for rest, replenishment and putting themselves in order. They didn't want to wear heavy army boots every day in conditions of relative calm.
Let's try to figure out what the German soldiers were wearing in this case.