Edited Characters must have real a real name

I’ve noticed after a recent update, once I’m done editing a character entry, I can no longer save the entry without something in the “real name” box. When adding characters to a book, the program has no problem with the lack of a real name, but if I edit character entries something needs to go in that field for me to be able to save.

Is there a setting I can toggle or something? Some characters just do not have a real name.