Part of patternfly/patternfly#7449
If you go to https://www.patternfly.org/components/navigation#horizontal-navigation or https://www.patternfly.org/components/tabs#default-tabs and reduce the page width, you'll see that the horizontal nav and tabs don't shrink, and instead overflow the main content container, preventing the scroll buttons from appearing. This is an issue on other example pages, too, (like table) but those are what were called out in 7449.
Part of patternfly/patternfly#7449
If you go to https://www.patternfly.org/components/navigation#horizontal-navigation or https://www.patternfly.org/components/tabs#default-tabs and reduce the page width, you'll see that the horizontal nav and tabs don't shrink, and instead overflow the main content container, preventing the scroll buttons from appearing. This is an issue on other example pages, too, (like table) but those are what were called out in 7449.