Pomodoro Clock - question

Hey All,

Looking to get some help with my setInterval function.
My intention is to have all of the below functions (set elsewhere in my program) to run once per second using the below code.

setInterval(function(){
renderTime();
writePomodoro();
tickDown();
writeRest();
endWork();
endRest();
},1000);

Thus far it works while my browser is active (My browser with issues is google chrome). However, if I open another tab or minimize my codepen (otherwise rendering it inactive) my interval clock is put on pause. It seems to work fine in other browsers like safari.

Any help would be greatly appreciated! thanks!
Here is a link to my codepen.