In this video, you can see two issues that are close to each other, but only one of them is displayed on the sheet. Why?
It’s because each sheet is linked to a model part bounded by two levels, and only issues that are located between these levels are shown on the sheet.
You can move the "missing" stamp a little higher/lower in 3D mode, and it will appear on the sheet.
You can choose which model parts are linked to a sheet. Learn more about this in Setting up 3D overlays for sheets video.