nHair collision not updating

[zeroonestudio]

Creating a dynamic plant with three branches and many twigs.

method: Dynamic Curve with IK spline to drive bones
Branches, a single curve/spline work fine.
When I create the twigs individually (as if they were just more branches) and they are parented/linked to the main branch the system works fine but since each branch has it's own system there are no self-collisions, hence no interaction with the other twigs.

If I build the twigs all in one system the self collision works but the collision objects (the yellow visualisation) remain in the same location as the first frame - as in, the curves update but the collision doesn't.

Any suggestions much appreciated

Cam

So in a nutshell - collision does not update on dynamic objects that are parented to other dynamic objects.

[zeroonestudio]

it seems the collision does not update with either set up. If I parent/constrain the follicle in the chain the collision updates and follows the chain but the twig chains fall off the branches!!?

set up at frame 0, collision in yellow

running the sim you can clearly see the collision altering shape but not position whilst the dynamic curve's position is updating

the outliner hierarchy