constrained RBD with collisionignore makes unexpected results

[dandeentremont 1]

If you look at the attached ColIgnoreA.mp4, you can see the "red" and "green" collisiongroup attributes ignoring one another. Results are as expected.

In ColIgnoreB.mp4, with those same collision ignore groups, I glue one red and one green sphere together. The free red sphere now collides with the green sphere, which is not as expected.

The best I can tell is that when these pieces are glued together, they somehow combine their collision groups. When I set collisionignore as "red green" it ignores them both. However I still want red to collide with red, so it does not work for me.

What's more is that Soft and Hard constraints work as expected, ignoring green sphere collision. Only Glue is strange like this.

Is there a way around this?

ColIgnoreA.mp4

ColIgnoreB.mp4

[dandeentremont 1]

bumpity