Kart barrel FTF

I‘ve installed a Kart Xact-fit barrel to one of my Range Officers. I believe the barrel is fit correctly with equal bearing on the upper pads, lower lugs, and no springing when in battery. It is the 4th or 5th one I've installed over the years. The headspace is .904. I intend to increase it to .908.  I have tested it with 3.8 and 4.0 grains of Bullseye, under a 200 grain lead H&G 68 bullet. The ammunition drops in the chamber easily. My recoil spring is 11 lbs. and the slide has a top mounted red dot. I am getting malfunctions where the fired case doesn’t eject, and the next round has failed to feed about halfway into the chamber. So, an empty case held by the extractor resting on top of the semi-chambered one. Upon removing the magazine, I can eject the empty and the loaded round drops down the magazine well. Before I begin experimenting, have any of you folks experienced this before? Or, do you have ideas for a fix? Thanks.

Check extractor tension

Thanks, I was wondering if that might be the culprit.