Here are some tips, hope they help.
You’re programming an interface, for which you need good troubleshooting skills which mainly consist of removing elements one at a time until the problem goes away. Your goal here is to find the source of the midi messages. You will need to know the basic MIDI message types, what is a status byte etc.
Temporarily remove all MIDI devices that are connected to your system
Configure MIDI-OX to display decimal instead of hex so you can understand the output.
Know what ports are open in MIDI-OX.
Use only one tool to monitor the output of the GR. You have the midi track input assigned to All Midi, delete the MIDI track or do un-assign any inputs or outputs to the track.