Anyone have a problem of gravity weakening? 9.8m/s2

What I’ve done is tested some actors by dropping them and getting their acceleration. If I drop it from a great height, it starts off at about 9.8 m/s2, but as time goes on it drops into the low nines. If I drop it from from higher, say hundreds of metres or thousands of metres, it can drop down as low as 5 m/s2.

At first I thought the physics engine was simulating wind drag, but then I looked it up and found that terminal velocity is reached very fast, so it wasn’t making sense. Now I realised I’m getting really inconsistent results all over the place. Is this happening to anyone else? You can see an actors details by either logging it, or making the variable visible or editable in the side panel, as it changes live during playing or simulation.