Take a look at profilebannergenerator.com. Some people say that when they enter the site, it keeps refreshing. I don't see the problem here but if two different people report the same issue, I guess it is real. Is there anyone who could fix it?
You need to find out more information about the people having the problem, what browser are they using? OS? etc.
They are using the same browser and OS as I, and I don't face any issues. I logged in in your computer with teamviewer and the problem is there. The FB login cokie doesn't get saved. The same issue appears on all browsers. I added the site in Chrome as a trusted site for cookies and the problem still remains..