Fields can't be empty after clone

I'm having an issue where I can't have empty fields on Cloned content.
So I can clone a node, change the title, save, works great.
But if I return to that node and edit to change other text fields I can update them (ex. '123' to '12'), but the fields can't be empty. If i remove the text and save, the text from before will be there. These fields are not required.

Any Ideas?