I've noticed that https://meta.wikimedia.org/w/index.php?title=Special:CentralAuth&target=%C9%B1 has no global account, and plenty of local only accounts. https://meta.wikimedia.org/wiki/Special:Log?type=gblrename&user=&page=&oldname=%C9%B1&wpdate=&tagfilter= advises that username is actually invalid. To make the case even more complicated, we have https://meta.wikimedia.org/wiki/Special:CentralAuth/%E2%B1%AE, which seems to be the same letter, but uppercase.
What did happen? What should we do to fix this?