Hmm. This site is hosted on a cldstr managed server; how did it save here?
Oddly, I tried to add that string on another site and could reproduce the problem. Then I typed in some other unicode characters and had no issue.
Perhaps a browser or something might be changing the encoding somewhere along the line? I'll have to investigate.
Created an example card in this support ticket and this website is just fine. All is well on this setup. I've had no problems with my other Postgresql setup, just this cldstr thing I fired up yesterday for testing. The browser is plan old Safari and the keyboard characters are entered via the macbook keyboard not copy pasted. It's a standard setup.
OK, thanks for the extra details. Very slammed this week, but I'm curious and will investigate as soon as I can.
Btw, we expect to focus on multilingual support as a top priority in Q1 of next year, so there should be a lot of related improvements.
...an update on this: a few immediate wikirate priorities have superceded the multilingual development, which is now looking more like a late 2016 or early 2017 priority.