Shortcuts: The “Open Safari” service could not be used.

Just got a brand new MacBook Air, and decided to try creating keyboard shortcuts for launching/switching to apps using the Shortcuts app instead of a third-party app like Keyboard Maestro. I created a shortcut for Safari, and now I when I try it frequently -- but not always -- get a warning/notice that 'The “Open Safari” service could not be used.' The various keystrokes I have tried using are not used for anything else. So why is this happening? Is this not supposed to work?

I also use Spotlight for launching apps, but I sometimes prefer a single keystroke alternative when I'm working.

MacBook Air M3, MacOS 14.7.1