An error I have been looking into on and off for quite some time, but have been unable to resolve
Once first Ball is locked, "Ball 1 locked" is registered, but no new ball is served, and the ball is only put back into play once the game activates all coils looking for a ball stuck somewhere.

I have replaced the "Lock kickout", "Ball lock 1", and Ball lock 2" switches, which did not resolve the issue.

Any ideas on what to look at next?

According to the switch test, all switches are working OK

Checking the ball trough, I can see that the "locked ball 1" is simply lying at the bottom of the Pop-up bracket, until all coils are activated by the machine and the locked ball is popped back into play.

Derived question is whether it should have rolled over to the Ball trough, or whether it staying at the bottom of the pop-up bracket is correct game behaviour?

Tested with a Ball and switch for Ball lock 1 stays closed
The requirement for the all coils shakedown to get the ball back in play, also applies when hitting “Bobs Bunker”, so I believe the Ball lock switch being the culprit can be ruled out.
I get no switch errors on testing.

Any ideal on what to check next?