Here's a weird one.
I'm enclosing a demo, but it's for a beta hold (Val Unrich) so I don't know how useful it will be. It was recorded using TCB 3.0.0.
The room in question is The Great Divide: 5N1E.
It is a room of mostly pit, with platforms and briar.
Here's the rough layout (simplified slightly):
P P P P P P P
P P P X X R P
P P X X X P P
P X X X X P P
P X X P P P P
P F P P P P P
P P L X P P P
P B L L P P P
P P L L P P P
P P P P P P P
Legend:
P = Pit
R = Briar Root
X = Briar growth
L = Clear platform
B = Beethro
F = Force arrow (pointing NE)
The lone briar growth on the platform with Beethro was originally spawned from the briar root up top (so was connected). However, it is not connected now.
If you look at the end of the demo, you'll see that on turn 432, the immature briar root on the platform with Beethro matures, and then on turn 433, it grows onto all adjacent platform spots. I'm not sure exactly what's causing this, but it's pretty weird -- it's not just a matter of going the wrong way through a force arrow -- the briar that matures and grows is completely disconnected from all briar roots -- no path at all.
I hope this is a thorough enough description. It may be redundant already.
Josh
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"
Rings and knots of joy and grief, all interlaced and locking."
--William Buck