If you think you may have changed the view settings there are a couple of things you can do to see if these resolve the issue.
Duplicate the view (with detailing if you have added annotation already)
Apply the appropriate view template to the view.
Alternate
Create a new structural plan view for that level, you will likely have to deselect "Do not duplicate existing views" to see the level you need to create a plan for.
![Plan view.png Plan view.png](https://forums.autodesk.com/t5/image/serverpage/image-id/250824i44E8299AB2FD3621/image-size/original?v=v2&px=-1)
If changes were made to the view template it may be necessary to start a project based off of the Structural template and transfer in an unmodified template.