Hi, thanks for your cumpliments. We're glad you like our software.
Do you use Camera->Distance Falloff ? This feature may modify the distribution when camera moves. This problem also may happen if render nodes don't use the same Forest version.
If not, please try to reproduce the problem in a minimal scene and send it to firstname.lastname@example.org. For large files, please use a web sharing service as WeTransfer or Dropbox.