Articulate Mobile Player in a loop

I have a course published for AMP, that I have viewed before on my iPAD, using AMP, all OK (sometime last year).

Looking to review it again today, I put the link into iPAD Safari. The browser immediately asks me to download and install AMP (which is already installed). I go the the App Store, open AMP and it takes me to its library (not showing the course I requested).

I have gone around the same loop after uninstalling AMP from the iPAD, reinstalling from the link just as above, then having the same result.

Do I have to re-publish the course? If so why?

Any help or advice is welcome!