Dwarf not receiving incoming midi through USB A

Using MOD devices
#1

One of my two Dwarfs are not receiving midi through USB A. Same settings and pedalboards on both units, containing only the Beta plugin Midi Display, same midi controller, same cable: One Dwarf displays incoming messages, the other one nothing.
Anyone come across a similar issue? Any help appreciated

#2

Wow, strange ! To be sure, you have 1 Dwarf that recieve midi and another one that doesn’t ?

#3

Exactly. Right now, I cannot see any other possibility than a hardware issue. The Dwarf receives midi through the midi port, but not through the USB A-port.