If a user does not have some bookmark permissions but tries to use the bookmarks next to the searchbar the searchbar simply disappers. When looking into the browser's developer tools you the a javascript error in the DropdownMenu.js.

To reproduce simple add a user and give it the role "Viewer", log in as or impersonate to the user, navigate to the host overview and click on the bookmark symbol on the end of the searchbar.
To verify it has to do with permissions add the role "Bookmark Manager" to the user and it will start to work.

Probably it is related to https://projects.theforeman.org/issues/30387 as we found this only on versions after this change.