Well ... In my case I did all the steps that Dan T. did and now it's saving! Thanks a lot! You solved the problem before apple. They would have to pay you for it! Haha! Sadly, I can't mark your answer as the solution because apple does not allow me to change the check mark. Thank you so much !.

This is disappointing!. It's been several days and apple is not able to give an answer ...

Good to know that I'm not the only one! In my case, I found that it only happens when I try to edit the App Review information.