If the "local" was turned off, that would do it as Bahamut mentioned. I'm not an owner of the XP-80. If the "local" setting didn't help (and it needs to be on), Maybe you have then "transmit channel" set to something odd. Like if you're in performance mode with a multi-timbral set-up and the 16th part lets say was set to mute or some patch that doesn't produce a sound, AND your keyboard is playing part 16 by mistake, that could do it.

I'd first check to make sure your midi transmit channel is set to something common, like 1 and that your "local" is on.

Best wishes
Bob
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