Based on the schematics, I am not sure I follow the you can not match or match feature does not work when set to add-a-ball. I agree with the spreadsheet shown by dr_nybble
Now the schematics are not always the bible, so there could be something on schematics, I am not seeing.
What I would suggest is get the game to the last ball with some scored value on the 10s point reel, and manually changing the 'No. Match' unit to that value. Then end the game. Does it give you a credit?
As your post states the number is changing, so we do know that the unit is working. As you can see in the spreadsheet above there is a 50% chance that if the match unit was on one of those numbers you have 0% chance of a match on the next game.