MIDI issues : no midi messages arrive to the midi in background rack

I’m sorry to ask for a so simple question but the midi in of my background rack don’t receive any midi message … it’s strange … I suppose one option was disabled accidentally but impossible to make something simple as relying a midi controller to the global master for example in the backgroud racke. The midi monitor of the midi in backgroud rack don’t detect anything (while it work perfectly if i’m not in the background rack).
Can you help please ?

Hi Pierre,

I’m not sure of your configuration so this may not be helpful but I usually have to use loopback ports to send MIDI and Audio data from the Song level to the background rack. Do you use loopback ports in your setup to the bg rack?