I think I know what this might be. You can open the .fpe file of your model (found in the entitybank folder. this file can be edited with windows notepad) and check if the line "collisionmode =1" is present.
If not: write it in. If its set to 0 or 2 (or whatever): Set it to 1.
f'None of this helps, send me the model via PM and I see whats wrong with it.
-Wolf
"When I contradict myself, I am telling the truth"
"absurdity has become necessity"
