Class bug?

Not sure if this has already been addressed, but it took me leveling up pass fifty to get a level forty class, and now that I'm past level sixty, I am still not a demon slayer. Is there more than a level requirement to attain a class (a single class, not combined). Or does it matter that I learned one skill point work of magic out of curiosity.
Becoming a dragon slayer happened before the magic, and after level forty.
Becoming a dragon slayer happened before the magic, and after level forty.