​[ASK] Occasionally Recognized as Someone Else, instead of my username

[kebunpedia]

Sometimes when I visit my forum (logged in and not logged out the last visit), I am recognized as someone else, not my username. I access the private message and I can see their PMs etc..

This happened among users who live in the same city, same region I think.

How to resolve? www.kebunpedia.com

Thanks