MSC10 issue with sysex transfer

Hello, i have one issue with MSC10 and sysex transfer...

Here is situation : i am using a doepfer regelwerk connected on ports IN1 and OUT1. My laptop is connected to USB

I send sysex of preset to laptop from regelwerk: it works

I send sysex of preset from laptop to regelwerk : it works

And then i try the same with pattern :

i send pattern from laptop to regelwerk : it works

But when i send syses from regelwerk to laptop : nothing..

When monitoring the midi messages, i see no sysex messages...

I tried to do the same with another midi interface (midiman 2x2)... and then everything works...

So for me the problem is related to MSC10.

Is there any concern with sysex in MSC10 ?? limitation of size for example ? Please support, thanks