Encores can be sensitive to both how the forearm is positioned on the rest and how the forearm is attached. Make sure you are consistent in how you place the forearm on the rest - most find it best to keep the rest as close as possible to the trigger guard. And you might consider adding an o-ring to each of the screws (others have used washers or even cutout sections of shotgun hulls) to "float" the barrel in the forearm - might need slightly longer screws to do this. You might also check to see if the ears of the forearm are touching the frame, but that usually introduces horizontal rather than vertical.
Just a Shooter