Nothing surprising. Also remember, there were people of colors who fought along the side of Nazi Germany and were in SS (around 40000 or so). There was entire regiment of them during WWII and many came from former German colonies in Africa like Namibia.
Slavery was justified by bible all the way in the late Antiquity. While many Christian thinkers thought of it as morally wrong; they believed it was a natural order of the society. In medieval times, and later during Enlightenment, Christianity in both parts of Europe justified serfdom, lets be Protestant church in Germany and Prussia, or Catholic church in Austrian monarchy. It was actually secular government that abolished serfdom in the 18th century against protest of clergy. French revolution abolished slavery after secular Jacobins with Robespierre got control of the government during the Terror. Church leadership did very little to improve people's conditions. They actually thrive in people's misery.