Foreground Service Notification Always Shown For At Least 5 Seconds

I noticed some very strange behavior when testing foreground notifications on Android 9. Situation: I have some foreground services where I don't know how long they'll need to run

Solution 1:

Latest security patch claims that it's normal behaviour: https://issuetracker.google.com/issues/147792378

However I'm not sure why it's happening already on Android 9.