I have had a situation just like this where almost the whole row worked and in the end it was a connector problem. I think the resistance varies enough that the signal for some switches can be read, and then there is one or two that cannot. Once that pin in the connector was redone, everything worked as expected. The move to the different board and everything started working also points to the connector being the issue as the Altek has a brand new header with less resistance than the previous board.