A couple years ago, Google decided that AMP URLs should trump app indexing URLs in the mobile search results. That has not changed, despite me complaining about it. I do wish I could let Google know that if someone downloaded my app, that I want them to go into my app instead of the AMP page from Google search.
I complained back then but even today, there is no way to do that without removing your AMP pages.
John Mueller from Google confirmed there is no way on Twitter today:
Not that I'm aware of.
— 🍌 John 🍌 (@JohnMu) January 17, 2019
As some of you know, we have a Search Engine Roundtable mobile app and it is available for both iOS or Android for free. It works pretty well and I occasionally push notifications for breaking stories using it. If you haven't downloaded it yet, please do download it - it is a great way to consume the content on this site - better than doing so over AMP.
I just wish that Google would use a searcher signal that if they took the time to not just download the app on their device, but also has the app installed on their device (two big big hurdles) that they default the user to the app URL not the AMP URL.
Forum discussion at Twitter.