AMP version keeps redirecting to normal page

I’m currently experiencing an issue where the AMP page is redirecting to the normal page.

So, I try and load an AMP page (ie https://www.zerotackle.com/rabbitohs-youngster-signs-on-40149/amp/) it simply removes the /amp/ from the end and shows the normal page.

I have this exact same setup on a few other sites and they are all working as expected. I’ve tried resaving the permalinks and a few other things but having no luck.

I’m on the latest version and looking at Google Search Console it started to get really bad the last few days.

The page I need help with: [log in to see the link]