I am trying to launch my App (parsing a pdf file and storing the aquired data to a database) via an intent-filter linked to pdf-files. Whenever I start the App normally, it will show up in the Recents Screen. However, if I use the View Intent/Action from another app, it will still behave as expected but it is not shown as an own page in the Recents Screen. Instead the app from where the pdf file is selected will be shown in the header and the app icon, showing the screenshot from my own app in the Recents Screen page anyway.
I already tried removing the android:label in the manifest file and I don't have the android:excludeFromRecents attribute set.
What other circumstances might lead to the described behaviour?
It is completely normal behavior. By default, started activities go in the same task ("page in the Recents Screen") as the activity that started it. This is similar to how tabbed Web browsers work: links normally open up a page in the same tab as the page that contained the link.
Where you see different behavior is because somebody took steps to change the behavior:
The activity that started yours could add flags to control task behavior, such as
FLAG_ACTIVITY_NEW_TASKYour activity could have manifest attributes to control task behavior, such as
taskAffinity,allowTaskReparenting,launchMode, etc.See the documentation for more.