Little problem with displays

We have tried to run an axon media server on a LED display and a tft monitor. Our problem is that the axon detect that both of them are outputs, and we don´t have MCA. But if we connect two tft, one is the output and the other one the MCA.
The LED display is connected through a capture device in a external pc.
And doesn´t matter what video output from the axon you use, it always do the same.

We haven´t seen any configuration menu or any reference in the manuals about this behaviour, and why the axon chooses automatically the output display and the MCA.