What's with those url changes? After a while about a dozen url anchors is cycled through which effectively kills the "back" functionality. If you go past them, you can't stay on the "main" page because another ones are added.
I am not able to reproduce that behavior on any device or browser I have at hand. If you experience that again, Please give information about the OS, Web Browser, and the URL you end to, and we'll have a look into the issue.