no. just try making a joint chain sepaate to your character and see if the same thing happens again - that way you can keep an eye on it and see when the symbol changes and work out what it is.

i don't have too much experience with rigging but it looks like you maybe have something connected to it - maybe an ik perhaps?

but really, if it's not messing you up at the moment then i would just keep working.

by the way - there's some nice scary work on your site jo.

eughhh....