Wormhole question

I have a bit of an enigma.

I'm playing in a game on the Yale map with the stable Ring of Wormholes
turned on.

However, very near the center of the map (5029, 4957), there is another
wormhole object that I scanned last turn. The game is now 53 turns
long and I believe I've had the center at least minimally scanned for
quite some time with small scouts crossing the map.

Is there any way for a Wormhole to just appear? Is there a Host
setting to place one there (I'm the host and don't remember any such
thing, but...?)?

Could a JumpGate scan as a Wormhole at a distance? There is a Scav
player and there was a UA player earlier in the game, so that may be a
possibility.

Any ideas?

Looks like it spontaneously arrived. I think I found its exit point.
It is almost on the circle that the original, stable, wormholes form.

Where in the HConfig do you set up the odds of a new one to show up?
Or is it just a flat change, possibly limited to whether the wormhole
ring exists?

Both ends don't seem to be in useful positions for me, so I'm just
happy one end didn't show up next to my Homeworld.