If in connected USB-Serial device real Serial number is formatted as "B4:3D:4D:B1:5A:C8" (as are in some ESP32-S3 Arduino boards), the plugin recognize only as "B4" and displays - serial_number: "B4".
Thus different boards with different real Serial numbers recognizes as the SAME board (same pid, same vid, and the same first fraction of serial_number).
At least on Windows 10 x64 platform.