1: Layers – the element could be in the wrong Layer.
Create a Layer Combination called ‘All Layers’ and have all Layers to ‘Show All’
2: Renovation Status – The element could be in the wrong renovation status
Create a Renovation Status to ‘Show All’
3: Hiding under a Fill?
Select the area where you expect to see the missing element.
If you can select it, change the ‘Display Order’ menu and ‘Bring to Front’ the element.