overdub and sustain overdub available on two separate midi commands

Hello,
I would like to have both commands available separately.
I see that if I assign sustain overdub to a midi command, it doesn't even react unless I go to Configuration>presets>sustain and bring overdub to the right column.
With such a solution I just have sustain overdub available: classic overdub ( toggle) becomes sustain.
Where am I wrong here ?
thanks !