My scenario: I’m generating MIDI from a custom software (no ReWire), sending it to a IAC MIDI port, then route that into Cubase. Audition is fine, but recording collapses all notes to start position.
This is five years later but did you ever find a solution? I have the exact same problem in Cubase 11. (External software sending MIDI notes via IAC; all notes end up at time point zero).