I have the same issue in Operation Thunderbolt and it's because the output states appear to be bugged in that game. If you inspect the states that are being sent, you will see this happening;
1.) A state of 0 is sent when a player's trigger is pressed, and a state of 1 is sent when the trigger is let go. I.e. the recoil states are opposite when compared to other games. This means that %s% cannot be used to dictate the recoil state.
2.) When a player presses their trigger, the system will immediately flip the other player's state to the opposite of what the current player is set.
If P1 starts holding their trigger, then this is sent:
P1=0
If P2 also begins holding their trigger, then all 3 of these messages are sent IF P1 is still holding their trigger. The result is that P2 will begin recoiling, and P1 will stop recoiling. (Remember, 0=recoil on and 1=recoil off)
P2=0 (P2 recoil on)
P1=0 (P1 recoil on)
P1=1 (P1 recoil off)
If P2 releases their trigger and keeps it released, then this is sent:
P2=1 (P2 recoil off)
P1=1 (P1 recoil off)
P1=0 (P1 recoil on)
If P1 releases and presses their trigger again, then this is sent.
P1=1 (P1 recoil on)
P2=1 (P2 recoil on)
P2=0 (P2 recoil off)
etc.. It sends the same initial state for both players, and then sets the other player's state to the opposite of the current player.
It's just a hot mess. You can't really use 2-player with outputs because of bad state messages being sent.