Hi Florian
1.) no-name USB-MIDI have only one feature: they increase the income of some chinese factory manager. They don't provide the feature to transfer MIDI (at least they reach the end of their abilities with sysex). So: put it to the dumpster.
2.) what software do you use? for receiving / analysing / sending the sysex data?
Regards
Florian (too ;-) )