1) We have A25-1000. Ours will send the ball into the waterfall or the bonus lane, with the waterfall being the far more common. Bonus alley for us is usually achieved with a little backhand flip from the right flipper, after trapping the ball. That brings up:
2) We have AF26-650, 30-1200. Only on the rarest occasion does either flipper do what you describe, though trapping is a trick because of the absence of return lanes. You should be able to stop the ball with the coils you have.
You've done well with your other switches. Maybe check your EOS for too early of an opening, or a heavy coating of the white stuff that builds up on high current switches. Or, maybe a wire on the flipper coil has severed some of its strands or cracked its solder? Or (this is common) see if the flipper button switch contacts are incinerated or coated with that white stuff.
Just some ideas off the top of my head. Good luck! The game is really fun when its dialed-in.