Hi Craig,
Would you mind to share for a moment the file?
I certainly will have a look into it.
I have attached an file that I created newly in R16.
The Group2 is of course outside of the Deflector, if that was you concern. I have integrated this step.
Perhaps, have as well an eye on the XP-manager, to see the flow/hierarchy.
As a side note, sometimes particles are just faster than the algorithm. Will say, they are too far away from the deflector to be already bounced, but in the next frame already to far behind the deflector. In such cases I try first to set up a second Deflector with settings that might catch the escapers.
All the best
Sassi
P.S.: …_02.c4d is just for fun.