This seems to be fixed in the version [PY] uploaded.
2.37.5 ... the version Testlund says he is using.
I find that gravity settings don't always 'take'.
don't know why ...
perhaps after changing it, he didn't hit 'change' to return to the sim.
who can say?
I do know that mutations ... ie ... the 2x or 4x slider ...
is not retained if one restarts ...
and is only there if one clicks 'change' to return to an already running sim.
so there are lots of those little quirks still to be explored.
with a sim that now runs pretty good without runtime errors ...
at least I can now start to experiment ...
to explore some of these bugs ... and report them.
who knows ... in another year or two ...
we might have 2.37.5 actually happening. :D lol