We are currently having a situation with our Jira platform whereby the summary fields are disappearing from issue screens (Company-managed projects) without the Site admin taking them off. This happened to all projects on the Jira platform making it impossible for users to create issues. This was solved by manually inserting the fields back.
Also, we have a situation whereby a particular field named "Category" is added to all screens in the project. This fields wasn't created and added by the admins. It is a system field and it can't be deleted. This issue was noticed last week and the field was taken off all the screens but this field is back in all the fields today without anyone adding it.
Jikes @Ismail Sanni ,
You might want to take this up with the Atlassian engineers directly so they can take a look at your instance and see if some app is adding a field or if you got a release rolled out which doesn't seem to be going correctly.
You can contact them at https://support.atlassian.com/contact