Delay when launching app

When I tap an app icon, sometimes it immediately starts, but sometimes I get 1-4 seconds delay before the app finally starts. I think it is 50/50 and also depends on if I have been in the homescreen (so maybe it has something to do with KLWP launching each time I unlock my phone or go to my homescreen?). I got this issue the second when I upgraded to Android Oreo a few months ago.