Missing Volume UI Overlay on Home Screen (Android 17, Pixel 9 Pro)

After upgrading to Android 17 on a Pixel 9 Pro, pressing the physical volume buttons does not always trigger the system volume overlay while on the Niagara Launcher home screen. Sometimes they show up, sometimes do not. The volume UI and mute/ring options are completely missing. This issue is isolated to the launcher environment; the volume panel displays correctly when using other applications, such as YouTube Music.