Yes this is a really troublesome bug. I don't know what "triggers" it but it's not exclusive to ChainWarden. Any skill with "unique" passive effects can run into this problem. (Chronomancer's Rewind, Pyromancer's Pyromania, ChainWarden's belt).
If anyone runs into this again and can explain what exactly they were doing right before they noticed it happening, that would be a huge help in tracking this one down.
If you are suffering from the bug, relogging can sometimes fix it, but if not, dying will definitely do the trick.