Some members having problems rating threads
 

Vbulletin 3.8.4

Some of my members are reporting that they can not rate threads because the forum software says they have already rated the thread - but they haven't.

One of my members rarely if ever goes into a certain section of my forum. She did today and tried to rate a thread. The forum came back with an error that she has already rated the thread. But she had not even been in that thread before.

Is there a way to see who rated the thread? Or maybe a rating history I can see?

Any idea as to what might be causing this?