The ZED 2i when connected to the USB port creates two devices:
-
2b03:f880→ UVC video module (USB3) -
2b03:f881→ HID sensors data module (USB2)
The fact that when you connect one camera another one stops to work make me think that this is also a power issue.
@adujardin already suggested to be sure that the expansion cards are correctly powered. Is the power configuration correct?