Steps to reproduce:

1) Create a content type that has a "Selection" fieldtype
2) Check the "Multiple choice" checkbox
3) Save the content type
4) Edit the content type again. Here the "Multiple choice" should be checked but it's unchecked

Due EZP-25002 it's difficult to have more than one option, but that can be achieved by saving/editing the content type multiple times. But even when we have more than one option, the "Multiple choice" checkbox status is not saved when the content type is saved.