No speed, no stop detection

I started Karoo2 in garage and put on a bicycle without speed sensor (wheel with speed sensor was nearby). Immediately I see karoo2 is not showing speed but distance and gps were working. That was recovery ride in neighborhood so I did not care much.
When I stopped to drink I noticed no pause on screen. Of course - speed is calculated as 0.

What was the software logic in this case? If I am clearly moving and able to draw a map and distance, why wasn't speed calculated from gps?