I've never noticed this before. On my Edge 1030 with the latest firmware, on a clear day, unobstructed view of the sky, central Florida, moving at a constant speed... To make sure, I tried this in my car on a flat/straight road with cruise control set... to make sure my speed was constant.
The speed metric varies a lot. For example, the once per second Speed data:
21.2, 20.8, 20.4, 20.9, 21.3, 20.5
I don't recall the speed value jumping around so much every second. Averages about 0.3mph jump every second, with some jumps up to 1mph per second.
I ran a CIQ app showing speed, and the native built-in speed metric side by side. Same thing. So it isn't a CIQ issue.
Anyone else seeing a change in the stability of the speed value? If the raw data is jumping around this much, then they adjust the internal smoothing function.