A couple of things to check on the outhole or any of the trough switches:

Check the "silver" lug of the switch. It's the one that sticks out like a thumb on the switch, and has it's own connector. Make sure that's nice and clean. They tarnish easily and can cause the switch to fail.

Check the wiring and connectors for broken or cold solder joints.

Check that the activation wire is high enough that the weight of the ball is centered on it and activates it--might be tough to see with the playfield down. But a hand activation isn't quite the same as a ball activation.

Last ditch effort is to just replace any/all of the switches that might cause the problem. I think there's like 2 that gottlieb uses in the outhole and trough. I had a similar issue in my Earthshaker, where the switches seemed to work fine in test, but not in game. Replaced with a new one since they're cheap and the issue resolved itself.

I suppose you could pull that board and just test each diode. I’m 99% sure that’s just the relocation of either the switch diodes anyway.

I know Gottlieb shared the columns (or rows, can’t remember which) with both the switches and lamps. Which adds a layer of complication.