Naomi or Capcom IO issue? 2P LK stopped registering during play

I had the Naomi setup using the HAS and Undamned adapters. And for some reason for the second player, it stopped registering LK. First we thought it was his stick, but I tried mine and it was the same. I tried rebooting and replugging in the adapters and no go. Then I checked if it was an adapter issue and it wasn’t as said adapter works on 1P with no issues. Then I thought it was an issue with the HAS, so praying it wasn’t the HAS, put in the Atomiswave and low and behold, it’s fine and it registers button 4.

I don’t know if this is a kick harness or Capcom IO or Naomi issue, I’ll check the kick harness later using my CPS2. Any thoughts?

Take the kick harness off. Take a piece of wire and ground out P2 LK. If it register then you have a bad kickharness. If it doesn't bad IO

I’ll give that a try after this event, thanks!

If you still have issues you can make sure the switch to the right of the test button on the Capcom IO is set to 2 player.