I’ve passed all other test cases. I initially thought it had to do with not removing the created setInterval, but I tried tracking the interval using state and removing that exact intervalID but still fail these test cases. Any help would be helpful. Thank you.
Here is my Codepen https://codepen.io/moises-lopez-ferretti/pen/QWBOpYp?editors=0011 
From a reset, it takes 2 seconds for your times to update after starting. This is usually caused by a setInterval() running its callback one second later and not immediately (there’s a simple trick to doing that…) and is a fairly common issue in the forums if you want more details to see if this is your problem.
It should be fairly easy to diagnose by logging the time when the start button is clicked and when the time is actually updated.