Royal Epiag china

I have what I would call a Royal Epiag tea service , consisting of a large tea pot, a cream and sugar and 6 cups with saucers . Could anyone tell me why the teapot says Czechoslovakia and all the other pieces say Germany. I have a few crystal items that my father won racing motorcycles in Czechoslovakia in the 1920’s and I wonder if this is where it came from .
Thank you very much for your time.

 

From online:
Both OEPIAG and EPIAG were associations of different potteries put together by the Austrian Government in 1918 to promote the sale of Bohemian pottery and porcelain. The name “OEPIAG” is an acronym for “Österreichische Porzellan Industrie AG,” which translates to Austrian Porcelain Industry. Any pottery with this mark generally predates 1920, when the name was changed Erste Böhemische Porzellan Industrie AG—First Bohemian Porcelain Industry—and the mark was switched to “EPIAG.”

As for the "Germany", maybe that dates the set to 1938 or later when Germany first annexed the Sudetenland, and a year later the rest of Czechoslovakia.