I had the same issue a while back. Check the EOS switch stack on the lower right flipper. The outside switch on this stack activates the upper flipper. It looks to me like you are not getting solid contact on this switch. There are two screws that keep this stack in place and if they get a little loose it's easy for the whole assembly to get pushed out of alignment. Adjust and tighten. If the mounting hole is worn you may need to add a toothpick and some Elmer's to give the screw some fresh wood to bite on.