Can't write names on signs because it censors it out.

I've been using signs more often recently (to write the names of places) and I've been having some issues. Whenever I try to write names down (for example, "Jack" or "Mary") it will almost always remove the words on the sign. No, it doesn't censor the words, it just straight up makes the sign blank. I'm not sure if this is intentional, but it sure is a pain. If it is intentional, then why? Why can't I write normal names on signs? That's incredibly painful. If it's not intentional, then it must be a bug. I'm not really sure what to do about it, but it's very hard to work around other than just not using signs at all, which defeats the purpose since I want to have names in certain places.