Disparity in tracking total day-wise non-AFK time

I’ve been using AW for tracking my screen time. I usually take the total time mentioned in the Category Sunburst. I recently checked the Timeline (barchart) visualisation and found that when I add the times on the chart, the total is an hour or so lesser than the Category Sunburst. There’s a similar mismatch when I add up by Top Applications or Top Browser Domains (to add context, I do use only Chrome on most days).
Would love to know how I could get the most accurate screen time.
Thanks!

P.S. I found a similar thread here: How to I get the total screen time