Brocock Sniper pellet feed issue

I have a brand new Sniper XR Magnum in .25cal that has random pellet feed issues with magazine only, so it's NOT a rifle problem. I purchased a spare magazine, and they BOTH have the same issue. Using the JSB Exact Kings Diabolo, pellets will randomly rise up in the magazine slots, and as it rotates for the next shot, and it deforms the skirt and/or cocks the pellet to the side, and will not load into the breach. Has anyone else experienced this phenomenon? Any tips ?? With the single shot tray in place instead, this rifle is insanely accurate and butter smooth. Thanks in advance.
 
Mine are 25gr. Pellets. Vendor said he had heard of issues with "some" pellets being slightly undersized for the magazine requirements. He is shipping me (free of charge) a tin of 33gr pellets that were a little larger and slightly longer. He stated that they have had excellent feedback using those instead. He felt that the depth of the openings in the mag was deep in order to accommodate MANY options, just not this one.