Is it a glitch or my Xbox?

    You are not alone. Since the newest update, I can save once, but only if the sim has just been made. Other than that, the auto save reads like it saved, only to find that it did NOT! While the physical save will crash whenever I make an attempt. 

    Sadly for me, this is better than it was.

It’s a glitch. I have the same issue. The Sims four is heavily broken at the moment.