if show Unknown device USB that mean the PC can trigger by the DSO ， not the same as printerpro, his DSO can not trigger the PC usb even to let the PC see it.
why the PC can not recognize your DSO and see it as unknown device , that may be two reason :
1 you have not installed a STM32 driver in your PC
2 the D2 ESD IC is broken , and it connect the D- D+ to GND so the PC can not Communicate with DSO , but the PC see the DSO so it consider it as a unknown device. if you sure you have installed the driver for DSO then you can remove the D2 from your broad to try again …
Regards
FreeZinG