Sorry, that's wrong. Eastern (Communist) Germany painted itself as an "anti-fascist state by definition", but in reality there were awful lots of Neo-Nazis active in the GDR - and after the Mauerfall Western cadres only had to move in to find faithful people. It's estimated that there were 15.000 (!) Neo-Nazis at the time. See https://www.deutschlandfunk.de/die-ddr-und-ihre-neonazis-rea... or https://www.zeit.de/2012/08/DDR-Nazis for more details.
This "the DDR was antifascist and there were no Nazis there" nonsense is a huge part of why the neo-Nazi problem in the former GDR was overlooked until 2015ff with PEGIDA and other violent far right movements appearing (for many uninitiated) "out of thin air".