I am having the same issue... There users just find it confusing having :iid=3&:embed=y#1 added to the URL. But it doesn't happen all the time.
Have you found the workaround and the reason for it.
we have found no workaround. if you find one, let us know. Or you can vote up these ideas:
Also, we were trying to figure out Tableau Public implemented the back button, but have not come to any resolution.