Notifications gone after opening app.

Okay so does anyone know how to fix it when you have say 5 notifications in the Notification Center for the the same app, when you open just one of those, the app opens, great, but then you go back to the remaining 4 notifications that were just in the Notification Center and there are NO notifications for the app that you just opened now. I feel like it may be in the development of the specific app, cuz I have some apps that the notifications won’t disappear and some apps that the notifications will disappear, even after just opening the app from your home screen, not even opening the app through the notifications in the Notification Center. Does anyone know how to fix this, if it can even be fixed???