On mobile web, discussion sections with certain characters in the heading don't open when clicked. The address bar changes, but the section doesn't open. There's no error visible in the javascript console.

I tested various characters at https://en.m.wikipedia.org/wiki/User_talk:The_wub/mobile_section_test, ones I found to cause the problem:

• – en dash
• — em dash
• " double quote (but not ' single quote)
• · dot

This is a fairly big problem, since it's quite common for users to "quote" things from the article in talk page headings.