I have similar issues. I think if you set the score based rewards to auto adjust(or whatever it's called) it helps.

My JY is not setup. But it should be similar to most WPC games.

There should be awards for things like score thresholds and things. Change the special awards free game (Credit) rather than ball. Something like that.

So under Adjustment Standard and Adjustments Feature check anything that says Award, Credit and E.B. Max E.B. is just one. The you may find another "something" awards and change from E.B. to Credit. Also it may say E.B. awarded for "Some Task", change this from Lib (Liberal) to Moderate of conservative.

You seriously will probably find about 8 different places under Feature Adjustments you never knew about where awards can be earned. Knock them all low, but don't ruin the game and make it too hard. I would suggest doing a factory reset (turn off and pull the batteries, put back it) just in case someone went in an made things real easy all over the place. After the factory reset you just lower the Max EB and set awards from EB to credit.