I checked several configuration about UDP packet transfer using xPico240.
I tested below 3 type of configuration.

All configuration we sent UDP packet from PC(1) to PC(2)

Conf 1)
PC(1) - - RS232C - - xPico240(client) - - Wi-Fi - - - (AP) xPico240 (MUX mode)- - RS232C - - PC (2)

Conf 2)
PC(1) - - RS232C - - xPico240(client) - - Wi-Fi - -AP - - Wi-Fi - - (client) xPico240(MUX Mode) - - RS232C - - PC (2)

Conf 3)
PC(1) - - - Wi-Fi - - - - (AP) xPico240(MUX Mode) - - RS232C - - PC (2)

In case of Conf 1) UDP packet did not reach to PC(2). Conf 2) and Conf 3), we can send packet from PC(1) to PC(2).

I think that Conf 1) and Conf 2) are same function of xPico240 with PC(2).