Unfortunately, history entries only appear under the latest visit, so with each visit, it moves up the list (assuming the list is in chronological order). If you want to view a page without adding a new visit, you can right-click > Open in New Private Window. But that trick isn't helpful for sites where you need to be signed in.

Oof. Thanks

Note that you can open the history sidebar in a new Private Browsing mode window to make this easier. That is what I do.

It would be quite easy for Mozilla to remedy this problem, which is quite annoying if one has to search out URLs visited over several days. Just provide a left pane period selection covering the 7 days before today. Then the new addition is out of scope and just disappears from the the current list. Try it with "Yesterday" to see. Of course, we'd like one for the 30 days before today as well.

Roger