Chrome vs. Firefox Document Complete vs. Fully Loaded

I am doing some work comparing webpage load times between Chrome and Firefox on different devices. However, as I have done tests, I’ve noticed something weird going on with the “Document Complete” and “Fully Loaded” metrics. On Chrome, these two values are different - document complete is a lower time than fully loaded, as expected (example Result URL ). However, on Firefox, these two values are, in my experience, always the same, which does not make sense (example Result URL ). Is this a bug with Firefox, or is it supposed to work like this? I am confused as to why this is occurring.