The check box caption is "Paddle only sidetone", not "Paddle only". It means sidetone that is produced only from paddle keying and not from computer-generated keying.
Some people (notably when using SO2R) do not want to hear any sidetone created by computer-generated CW, and turn their rigs' monitor sidetone off, but when using paddles, they need sidetone from the keyer as part of the hand-ear feedback they need while using the paddle. Other people leave the rig's monitor sidetone on and do not want to hear any sidetone from the keyer, regardless of the keying source. That is why there is an option for paddle-only sidetone.
---In N1MMLoggerplus@..., <rclee@...> wrote :
Unchecking Paddles Only worked. Apparently it's more than paddles only. It turns the ST on. Thanks everyone.