MapCppTrackerMCDigitization uses srand(time(NULL))
The noise code in MapCppTrackerMCDigitization is based on rand(), and has a line setting the seed from the current time:
MAUS policy is to have the MC produce the same result each time, using a global seed. This is defined at the level of a GEANT4 primary particle. Using the current time as the seed will break this policy.
The fix should be relatively simple, as srand can be passed the correct seed value. I'm assuming that some example code can be found relatively quickly (the seed is a data member of Primary.hh).