In the following, I'm assuming that when you say the 'Ejectors work when the gun is dry fired'..that means they snap when the gun is opened,
But, that you do not have any fired cases or snap caps in the chambers.


This is all about the timing of the Ejectors release..so it may not even apply.

The Ejectors may be releasing a bit early. When that happens, you hear them snap, but the rim of the fired hull is not totally clear of the standing breech.
So the bottom edge of the fired hull strikes the top edge of the standing breech upon ejection and goes no where. It pops right back into the chamber.

Opening the gun very slowly after dryfiring with a snap cap or fired hull in place you can sometimes actually see the early release of the ejector and the hull strike the standing breech instead of launching over it.

Put the bbl's in a padded vise helps and gun horizontal when you do this helps even more as you can use 2 hands to slowly and with control open the breech by lowing the action and watch the (dry) fired hull being lifted and then ejected,,and at what point.

If that is the problem, the Ejector can be made to release a bit later by adjusting the Ejector Sear in the forend.
It takes a very tiny amt of change to effect what you need.

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Another problem of why the Ejector snaps too early may be a weak Ejector / Ejector Sear engagement ,
These two parts have a squared 'sear engagement' much like a trigger mechanism.
If one or both parts is worn or has been worked over in attempts to change or somehow improve the Ejector timing, that Engagement my be less than secure.
If it was a trigger,,some would use the term ' hair trigger' to describe it

The parts are hardened, Case Hardened usually. Don't try bending the Ejector Sear.
But if the engagement is weak, the angle off...just like with a trigger, it doesn't take as much pressure to release it.
So when the gun is opened the Ejector Sear is push out of enagement with the Ejector (Kicker) too quickly and the early release of the Ejector occurs.

Might not be the problem,,but a couple things to check for