I have a Remington 1100 12g 2 3/4 only 30” barrel. I have had the gun for around 8 years now and up until last fall it has worked flawlessly! Now randomly it doesn’t want to eject the shells. I thought it was just dirty,I have gave it a few really good cleanings and still nothing has changed. Some high velocity shells will eject but not all 3. Ever. Am I missing something?? I also changed the rubber O ring.