Device assignment failed with 2 devices

Followings are the detailed explanation about this problem:

1. One netX board is connected to PC via USB and the otner netX board is prepared to connect the same USB port. (LFW are already downloaded to both of netX boards.)

2. In Sycon.net, I can see the device on the device assignment window as the attached screenshot-1 and at this moment I can see the correct channel protocol as well.

3. After then, the other netX board is connected to the PC via the same USB port (means the previous netX board is unplugged from the PC) and I can see the device on the device assignment window, but, cannot see the correct channel protocol and it shows as "undefined" as the attached screenshot-2. In this case, if I try to download the configuration to the device, then, Sycon.net generates an error as the attached screenshot-3. To recover this, I should stop and start ODM V3, then, working again.