Addon only working on testing. Window.onload not working

I tried what you suggested but it didn’t work. Someone else suggest:

AJS.toInit(function() {
 alert('hello world');
 console.log('Hi!');
});

This worked. but it’s not working for my function changeCSS(). What i’m changing is css on a kanban board. Not sure why it’s not triggering for this specific instance.