while there is a problem with the command
the normal player should not use a @commands while is attached to an npc
this was fixed in this commit
https://github.com/rathena/rathena/pull/4043
but either ways , if you are testing it would be a gm account
and by default an account with group 99 command_enable: true
so i think the bug you experienced wouldn't happen to the normal player anyway
edit : tested the command , and the problem would happen anyway cuz the bug
https://github.com/rathena/rathena/issues/4366