FTP TEST NOT WORKING IN GARMIN EDGE 530

I updated from edge 520 to edge 530. For the latter I have done twice the FTP test following the seven steps in the current protocol. Despite both, HR and Vector3 power meter are working properly, the two times I have got the message "Unable to calculate FTP value for your workout. Try again". In both test I have finished, and apparently the data is clean; as I can see in Garming connect and in Strava. Does anyone have idea what is wrong?

Thanks

Jorge