With the moderator off the gun, do you hear any rattling inside the moderator when you shake it. This would be an indication of pellet clipping/shaving and you'd find loose lead inside the monocore if you unwrapped the felt. You'd probably also be able to shake it out through the front cap.
If you carefully (I use a strap wrench-a steel pliers will easily gouge the annodizing and aluminum) unscrew the endcap you will see the caliber of the monocore etched into the back end of the monocore. It should say .22/25 cal based on what you ordered.
As far as far as basic troubleshooting, check to make sure the adapter is fully seated in the threads, that the Sumo is fully screwed on (hand) tightly and that the endcap is flush and tight on the body of the moderator.
Aside from finding misalignment of the moderator, the most common thing we've seen is the barrel being uncentered within the shroud. Our adapter has a centering function, but it isn't a press fit. There is still some side to side or up and down space between the adapter and the barrel.