Checkbox "Required" in object

Today i appears a bug with field which i have marked a checkbox “Required”. I don’t know when this bug is appears but it exsists for only this. Others fields which have selected this checkbox still works bug.
I can’t described how to redo this error.
I only want write it down that sometimes could someone have this bug.
I think that is only one solution. Remove this field but i don’t know this good.

Maybe it could appears because i use the same name field in few object of type and then db may have problem?

I think I did not explain what I meant in the description of the situation and i should it.

The thing was in this topic that when I selected the type of checkbox with a given name “required” in a different type in the other type, the same field (checkbox - with the same name) was also marked as “required”, although I did not make such a selection.
i don’t know for this moment that this problem still occurs but maybe you should check