Hi
Recently I see strange duplicates in history view like this:
How can be fixed?
Well, i think the history get’s a little more crazy with every new release https://github.com/home-assistant/home-assistant/issues/6902 
But maybe it’s related to your database? If you can live with loosing your history, delete or rename your database file and see if that helps.
Actually, after I saw it at first after the upgrade, I erased entire database and recreated it. 
Still the same no luck
You probably have two devices with the same friendly name. I have that problem and have gotten used to ignoring it.
Yes, probably that’s the reason. I have a group and a switch with the same name.