Here's a job control conundrum for you.

[Michael ODonnell]

kill is a shell builtin (assuming you use something conventional
like bash or tcsh) and has access to the shell's internal
bookkeeping.  And that '%1' notation (*only* meaningful to your
shell) is a shorthand reference to a specific job spawned by
your shell.  So if you tell your shell to 'kill -1 %1' it can
easily make use of that insider knowledge to determine exactly
which job you're referring to and how to signal it.

By contrast, killall is an independent app that can only see
what's running on the system by using "normal" techniques like
poking around in /proc and such.  So if there's any ambiguity
about which process you're referring to it's probably choosing
not to kill anything rather than to kill the wrong thing.

You didn't supply much info like how you launched the app.
Have you used something like ps to verify that a process of
the specified name is actually running?  Maybe it's renamed
itself, or maybe alpine is a shell wrapper around a binary
of a different name, or maybe you no longer have sufficient
permissions to kill it, etc, etc...