Try removing/replacing the tiny filter capacitor on the switch row/column in the switching matrix.

During test mode, ONLY the switch matrix is running/repeating, giving it a more efficient scanning time to read the switches, so switches will all work more efficiently.
In game mode, ALL the matrixes/solenoids/scores/buttons are being read/updated repetatively, thus less time-slice is used to process each matrix.
So, with a slightly dodgy matrix cap, it will be partially filtering/missing the switch closure pulse, therefore not responding in gameplay.

Since you've now replaced the switch itself, it's pointing more to the matrix again.

MM