Quoted from razorsedge:
Can confirm this happened with my game, in my case it was a connector needed the wire pushed in a little further to the IDC on the connector under playfield for the first opto transmitter. I guess the transmitter not being active meant the game thought there was a ball in the first lock (attract mode or not). For my case punching in the wire better solved all the wierd behaviour. To find the cause I checked the opto transmiters with my phone camera and found the first TX was not lit.
Nice find! That would definitely cause this issue.