A bug in Chat plugin? Chat corner pop-up, pops after closing

I activated the chat plugin in my BuddyPress+WPMU project and a few users was complaining about the chat pop-up keeping popping after they close chat… As I did not find any problem I thought it was a browser problem, but now, this problem happened to me…

I recorded my screen to show how the bug works. I closed this chat yesterday at morning and it keeps popping unto now! I disabled and enabled the chat plugin again and the problem keeps working, I closed the chat of the user that was chatting to me, and to him it is not happening, just to me…

To you to see, this is the screen record:


What can I do to close this chat and finish this bug?