While editing a report, there are two reasons that you might not be able to see your Defects.
You're in an Informational ONLY Section or Item. Inspection details and the General Items of each section are Informational only, meaning they only have Info and Limitation comments, not defects.
If you want to be able to add defects to those section, you can turn OFF the Info Only rating by clicking the pencil icon that shows up when you hover over the name of the Item:
Then disable the info only rating:
You'll now be able to see defects.
2) You're using Classic Item Ratings and you haven't hit the "D" defect rating.
If you are using the Classic Ratings Sytem, You'll need to hit the 4th defect button to reveal the defect categories.