In the most recent update to nautilus, the behavior for the ctrl + page up and ctrl + page down hotkeys was changed, and I don’t think the new behaviour really makes sense.
When you have two or more tabs open, you can press ctrl + page up or ctrl + page down to switch to the previous or next tab. In nautilus 42.X and below, doing this when you got to the first or last tab would wrap around the beginning or end of the tab list. For example, if you were on the last tab and pressed ctrl + page down, you would be wrapped around to the first tab. This was good behavior because you didn’t have to go through the entire tab list to get from one side to the other, and it didn’t require as much thought to get to a tab. Not to mention that if you only had two tabs open and you wanted to get to the other tab, you didn’t have to think about whether to press page up or page down because you would go to the next one regardless of which one you pressed.
The new behavior in nautilus 43, however, disables this wrapping feature. Instead, it plays an error sound and does nothing. I believe this new behavior is inferior to the old behavior and the change that enabled it should be reverted. The old tab-switching behavior was consistent with other applications, such as modern internet browsers, the menus in many video games, and countless other things that accomplish a similar task. Even vim makes both switching tabs and searching wrap by default. Limiting this shortcut in such an arbitrary way doesn’t seem like a change that benefits anyone.
I love the gnome dev team. I think they make a lot of good and interesting choices when it comes to design and user experience, but this change doesn’t seem to align with that. If someone knows the reason behind the decision to disable wrap-around, I would love to hear what it is; but as it stands, this seems like a silly change.