PXI 2596, Outputs different simulation results with different Instrument Drivers

[MCKR_1009]

Hi all.

I am using the PXI-2596. Basically, it is a Dual 6*1 multiplexer. I have used both the "NiSwitch Connect channels" API and Relay APIs to connect the channels. But both are behaving in a different manner. Which of the below behaviors are correct behaviors?

Behaviour with "NiSwitch Connect channels" API: I have used NI-Switch APIs. I have connected one channel (ch1A) to the common(comA). Then I have tried to connect the (ch2A) to common(comA). Then I got an error with the message "One of the channels is a configuration channel that is in use or is a common multiplexer channel that is in use." This means that we can't connect second channels without disconnecting the first channel. The code which I have used, Error message and Simulated output screenshots are below. 

Behaviour with "NiSwitch Relay Control" API: By using this APIs I am able to connect both the relays k1 and k2 without disconnecting k1. So I would like to know what is the correct behavior of the instrument. The screenshot of the code, the Simulation result is below. Also, You can find the VI which has both the codes in attachments