All spawned Courtiers get the same surname.

[von Fulda]

I first discovered this as a Norse, Germanic custom character in the Baltic. All courtiers I spawn from the events page ie (present debutante, and invite noble to court) get the same surname. This bug has also been observed as an custom Catholic, Englishman in India.

Verifying game files on steam did not affect this bug.

 

[von Fulda]

It is now apparent to me that playing as any custom lord will result with the bug.