Is the ejector actually tripping and kicking or is the unfired case just "hopping " out ? I ask this as it sometimes happens that the the gun seems to eject but doesn't actually trip. Dose it eject on opening with out firing ?
If the cocking dogs are strung it may be the dog spring has broken so that it engages and trips .If the cam is worn or loose then they may not be coking fully ,other than that without knowing the type of ejector work in question I'm out of ideas .