NES Four Score/Multitap not working

Hello, I’ve been out of the loop for quite sometime. In addition I’m using a very old setup (Retroarch 1.0.0.2 on iOS 6.1.3) I have tried the Nestopia core and the main NES core I am using is the FCEUMM one.

I’m trying to get 3 controllers going so I can play four score games with 3 players (Bomberman II, Gauntlet 2, Super Off Road). I configured the controllers inputs but the 3rd controller just will not respond. I read under FCEUMM device type user 5 needs to be set to multitap, which I did, no success.

I would really like to play these games with more than 2 people. Alpha Final Burn (Arcade) and Mupen64 (N64) responds with 3 controllers, so it suggests to me it’s not an issue with Retroarch but perhaps specifically the cores I am using.

In addition, I notice if I load Bomberman II with Nestopia and try to go into Battle Mode, it just makes the equivalent of an error sound. But if I load it with FCEUMM, it will at least get me into Battle mode with 3 players, it’s just player 3 doesn’t respond.

Does anyone have any knowledge of how to get 3-4 player NES games working? I would really enjoy being able to play these games with more than 2 people.