Can someone confirm or deny that making the Logical Volume inactive and then repeating the chcon should change the link to the correct context?
First off don't use chcon.
What's the output of restorecon -Fvv /path-to-file ?
It seems very odd in the first place for anything in /dev to have an incorrect context given it's a virtual filesystem and as such the contexts handled by the kernel...
Unless of course someone messing about with chcon broke something...