I put down a bunch of signs within the world with text, did some other activities, and when I logged in again the text had disappeared from all my signs. I put a new sign down with text, it displayed as before. I immediately saved and exited the realm and then logged in again and the text was gone. both times I was the only player on the realm.

The realm owner logged in and the signs were all missing text too.

When We were both logged in we could not see each others text on the signs either even though they displayed for our respective players at the time we put them down.