Unable to change A.R.T Spine/Neck bones

Hey there, for some reason recently I cannot change the number of Neck and Spine bones from their default value.

When changing the 3 Spine bones and 2 neck bones to lets say 1 spine and 1 Neck bone, the A.R.T plugin changes the value back to 3 and 2 (default). It didn’t used to do this?

I’ve tried to change the script file to the newest 4.4 version, but still doesn’t seem to change the outcome?