why some fields hidden from node?
I it been a long time that you created that content type ?

It is on a production website already ?

Are you working on a fresh Drupal 7 installation ?

You could delete and recreate that content type if there is no serious impact on your site or your data.

If you do that, then your can check if the situation happens again. Sometimes there are particular manipulations while working that are responsible for those situations (and you can find out if you did something in a certain way the first time).

But remember : to me this operation depends on the 3 questions that I've asked on top of this text.

Does it help a bit ?