My target settings were changed?

[Niwashi]

Check your target filter settings. I believe L3 (left stick button) by default will swap filter settings (All, Others, etc).

That's a different issue. He's not trying to change targets but getting the wrong thing targeted. It sounds like his issue is more about UI focus than targeting. He's getting the X button's Action function (just as though he weren't on the chat box) when he's trying to send messages. It's more that the chat box is losing focus while typing with the controller, so instead of Send (which is the chat box's "Action"), he's getting the default action of whatever else is around (which is generally select or initiate dialog).

I don't know if the same thing would be happening for me or not as I don't use the controller for chat. I have an attached keyboard for that (though I use the controller for everything else).