This is very annoying(and interesting).

First, I activated SLD trados on laptop with a USB monitor(via subscription), then after disconnecting USB monitor and launching SDL trados, the activation is revoked.

Second, I launched (successfully activated)SDL trados with the different USB device configuration(this time, connected with external USB SSD drive), then the activation is revoked.

Would somebody let me know why this happened?

It seems that SDL license authentication process is connected to USB device configuration also. 

It seems that SDL license authentication process does not authorize the configuration different from the original(when activated) configuration. The interesting & annoying thins is that the configuration change is related to portable USB devices, such as USB monitor, USB Portable SSD storage, and advanced USB hub(which is recognized as a device on Device Manager).