I also have this issue with FP5 and figured how to reproduce it:
1 Go to app listing / search
2 enter something to search app
3 pick app
4 when in app, press backwards button
5 you get back to app listing / app search
6 Now if you press any of the apps it will open app with wrong index
lets say with out search you have linkedin as first app, you search teams, go teams, and the use backwards button to get back to search. Now you press teams again and it will open linkedin even though icon is teams icon. Problem probably is that app listing does not retain index or refresh it according to search parameter and opens app with same index as if you did not do search. Basically you have miss matching icon to index that launches the app. I would either save index so that when users gets back to app, it is loaded, or refresh indexes when user gets back to app.
at least for me animation duration speed is 1x, still launches wrong app. I am fairly sure it is because indexing changes on background as I wrote in my last message. Nothing to do with animation or how fast you press the icon. It is related to android working in a manner that when switching between apps it destroys all app data that is not saved and app listing does not save indexing correctly or do reindexing again when user gets back to app listing. so pressing first app of the search result would open app that is first with out the search.