I can never get the Open In Reddit app button to work. I’m on iOS and have the latest version of the official reddit app. Which btw is painfully filled with ads.
May I recommend using any 3rd party app for reddit instead of the official app. I use relay on Android and it is great. There are many other options, all of them are better than the official app.
Unfortunately no. But there's an "Open in Apollo" option from the share sheet which works for me. It's just an extra tap to open the share sheet from the AMP page.
It never works for me either, but there is a workaround. If you click on the 'x comments' link at the bottom of a post, it will open up in reddit is fun.