Another thought, with the barrels off the gun, try sliding the ejectors back and forth in the underlugs to see if they are binding there when moved individually and when moved together. Check it against the gun that works properly. Might be a little light oil lubrication there will resolve the problem. If you can take them out of the underlugs (should just be a single set screw holding them) and clean the channel and clean the rods. If there is corrosion remove it with a scotchbrite pad, relube and try again. Check their fit at the face of the breech as well. I had to stone the edge of one ejector to get proper fit and polish with emery the rod on another to make it operate smoothly. This is a lot easier than adjusting the timing and you can do it without fear of hurting anything - if you detect a problem there.
