A few days ago, Google made a change in the Google Search Console page experience report to direct developers to debug their AMP pages for page experience issues outside of Search Console. Google is linking them to the AMP Page Experience Guide.
Google said “this new functionality will make it easier for you to act on performance issues reported by Search Console.” I would prefer Google keep it all in Search Console, but I get Google does not want to maintain multiple debugging tools.
So now if you go to that page experience report, click on an AMP URL to debug, you will see this link that says “AMP PAGE EXPERIENCE GUIDE” that links you to that AMP Page Experience Guide for debugging.
Here is a GIF of it in action, which may be a bit hard to follow:
Forum discussion at Twitter & WebmasterWorld.