What AMP plugin do you use?
And do you use a caching plugin?
I’ve just installed Fast Velocity Minify and Redis Object Cache. Planning on installing WP Super Cache for static cache if pagespeed ninja doesn’t work. But if it works, I’ll remove Fast Velocity Minify and WP Super Cache, because I think itself as well has static cache generator, just not sure if its fully functional as WP Super Cache and has pregenerator.
I’ve just test PageSpeed Ninja with AMP plugin, and there is no conflicts (PageSpeed Ninja nor optimizes or caches AMP pages). Most likely there is a conflict with other caching or optimizing plugins. Could you send me ([email protected]) list of all active plugins on your website?
I’ve sent you email 5 hours ago. 🙂