Transferring Scores to On-line Facility

If I modify a score and upload it on to the MuseScore on-line facility, it happens quite quickly.
Why now, when I try to up-load my new MuseScore music to the MuseScore on-line facility, although I get a 'success response' it never appears as one of the five on-line scores, and with one of the existing scores being deleted to make room for it?

Thank you.