Ecoda is the correct switch brand. I mentioned Chieta earlier, and they may work, but I have only tested the Ecoda 22KHz switch in front of two Ku motors.
The 22KHz switch does not separate power between the two ports. Motor and switch commands are also sent down both sides of the switch, and this is why both of your motors move at the same time. You will need to disconnect each motor, erase the prestored settings in them, and reprogram them one at a time using different Diseqc 1.2 positions for each motor if you do not want goth of them to move every time you change satellites.