I felt very proud of myself. I put in the time and effort to search out the rare mob spawn that can give you the Vampirism active status effect and I succeeded in contracting Vampirism! Huzzah! I did the thing!
...except after traveling to several of the wayshrines in the area, I was never offered any sort of quest to seek out a Vampire Alter. Well, poo on that, I'll just go to the Vampire alter myself and click the scroll - same one that appeared for one of my other characters when I had a guildy bite me!
...except after traveling to all 3 Vampire Shrines, I've discovered that the scroll simply fails to appear.
Something is broken with becoming a Vampire on your own.
It seems I am left with no other course of action than to cleans my hard earned Vampirism active effect, and again beg a guildy to bite me. I only 'complain' on here because it's sucked the fun out of my self accomplished goal.
I even waited until after maintenance to see if that would correct the problem. It did not.
I don't know if this is on anyone's to-do list at ESO, but at least now you know about it. (Even though the bug reports category is locked currently for some reason)