Might be iOS only? Needs verification on Android.
When I want to get the widget view graphs details pop-ups I would expect the pop-ups to appear for the initial touch down event, then being able to slide along for the pop-ups to show the history details.
The initial pop-ups, and it's related vertical time line indicator, only show up with by first touch up event though.
Making it a bit unexpected and awkward with touch down - wondering - touch up - now I see them - touch down again and slide to get what I wanted.
Same when the pop-ups and time line indicator is already showing, touch down at a new location doesn't do anything, as would be expected, only touch up again makes the indicator and pup-up values jump to the newly selected position.