I've noticed that when I have multiple devices that contain multiple midi ports, that ShowXpress doesn't use the full device/port combination. What this seems to cause is that it selects the wrong device's 'Port 1' - if that device shows up first in the list. Changing to the other 'Port 1' doesn't seem to take effect even after saving and restarting the app. I've randomly gotten it to work, but not consistently.
I have been able to get around this using virtual routing with MidiPipes, but think this should be addressed if possible in ShowXpress. Other applications, display the full device name and port number. So for the example screenshot I'd expect to see:
MPK88 - Port 1
MPK88 - Port 2
MPK88 - Port 3
Scarlett 2i4 USB
SSCOM1 - Port 1
SSCOM1 - Port 2
ShowXpress - Mac version 7.1.74 - 151106
How Logic Pro X displays device ports
Midi Setup