Is the Create Change action manual or automatic? The template set on the action is only used on manual actions but it should work fine. You could try seeing if having the attributes visible on the window makes any difference?
The action is a manual one set from within the Status actions. My users click Create Change and the correct process is selected. The Template is used just to select reply addresses. I have added the attributes to a window and tested and it does work from the shortcut bar but not from within the process.
We have never noticed this before as we used to set the process reply addresses from the inbound email section without using Inbound email, but we have had to use it for something else and decided to use templates instead.