This refers to both, Garmin Connect website and Garmin Connect Mobile application.
Currently it seems, I cannot change the climbed floors goal. It is stuck at 10 floors, and no other value is accepted. E.g. if I set it at the website in the appropriate field, then change to another page, e.g. calendar and then back to the device properties and user properties, it is reset to 10. Synchronizing does not help either.
The GCM application even says immediately after changing the goal "an error occurred", and stays at 10. Maybe someone at Garmin could look into that issue and fix it please.