Average Visit Time Calculation

I'm testing on a site where users load a web page with inline video and often stay for long periods of time.
Running Umami and Google Analytics in parallel has Visitor and Page counts in the same general ballpark but Visit Duration in Umami is 1-2 minutes where Google Analytics shows as 40min to over 1 Hours averages. The longer duration is more correct for this site.

Is there a default timeout or delta between page views that can be tweaked in code or possible exposed in configuration?

To experiment, I added client side code to register an event every minute to see if that had any effect on average visit duration and it did not appear to even though Umami did track thousands of events.