Public course not appearing in search or on profile?

I’m learning this course: and I noticed that I cannot see it on my profile, nor can I see it on the profile of another person taking it, nor can I find it in search, nor in the category that it says it’s in. It certainly seems to be public and I’m sure I found it as public.

I’m curious because if this course, which I find quite useful for me, cannot be found by me when I know it exists, then I wonder how many other courses are hidden for no apparent reason.

Perhaps it was changed to unlisted at some point and this just doesn’t display at all?

Rather frustrating user experience (rather like the pointless UX changes, or the inconsistent decks split or so many other aspects of this site but I’m trying to not make this a general rant ; and FWIW, of course, yes, I do find the site useful enough to put up with its many…quirks.)