Czechoslovakia, Hungary, and Poland were independent countries, not regions of the Soviet Union although they were dominated politically and militarily by the USSR. The Soviets influenced their domestic policies (more or less, depending on what we're specifically talking about) but didn't run them directly, so yes, the different Eastern European Communist countries did treat religion differently, and they pursued different policies at different times as well. Each of these countries also has its own particular religious history, so there's much more to it than communism when it comes to why the Poles report such high levels of religious affiliation in comparison with the Czechs. I wrote recently about religion in Czechoslovakia here, /u/0utlander wrote more about the roots of Czech irreligion here, and /u/shotpun wrote about Catholicism in Poland here, and there are a bunch of other threads about religion and communism in Eastern Europe as well. I couldn't find anything specific about East Germany and don't know enough to provide much of an answer. It's worth mentioning that this part of Germany has historically had a Protestant majority, so there are difficulties in comparing it to Catholic-majority countries like Poland or Czechoslovakia.