Hi @romane2m, you should only need to run the calibration routine once per new user and certainly the calibration profile is maintained after shutting down power or restarting the system.
Can you confirm that this is not the behaviour? If you simple try to access the gaze data directly in your program without calibrating, is there some error message or lack of accuracy? Thank you for the explanation.
Also, out of curiosity, are you able to reproduce this situation in Windows?