According to this post by @HoneyBadger there was a forum maintenance last Thursday. Ever since this maintenance I can no longer save changes to my signature. IIRC it worked the day before.
Whenever I edit my forum signature and save it, the system will respond with “Saved!”, but in actuality no changes will be saved. E.g. when I click on a category or the “Topics” menu item and then go back to my signature profile, the signature will shown the previous content. I tried different browsers and also cleared my browser cache, so it seems the problem is not on my side.
You’re quite right, it doesn’t seem to be working. Let me see if there’s something up in the Discourse notes or if someone else has raised this as a bug already.
FWIW, there is also weirdness in how the forum is interpreted on iOS (latest version, running Safari). The cursor will be in a different line, sometimes off by one or two lines. This comes up usually as part of editing a previously-submitted posting. So you have to position the cursor two lines lower than the text you’re trying to correct / amend. Saving changes may also not work.
I saw similar issues with mobile browsers on Discourse (here and other places) and even the old Xenforo so this didn’t surprise me. Chrome seemed to be “less awful” but I think I even saw it on desktop Firefox.