Normal
This is news to me. Are you sure you're not thinking of phase shift introduced by the filters you're adding? I'm not saying its not possible for a processing block to add latency, but I do not recall this being a problem while designing presets using the DriveRack PA. Then again, I always measure while I'm doing my alignments, so a small amount of latency over what I expect from the filters I change could sneak by me and I would compensate for it without realizing.