You have removed several backup archives or have backed up a significant amount of data to the Cloud, but the Storage Usage still displays old values.
Cause
Currently, statistics are recalculated every 4-6 hours; then the new values are displayed in the Management Console and Backup Management Console (both for Acronis Cloud and Service Provider hosted storage based on Acronis Storage or Acronis Storage Gateway).
Other possible cause is that some old or incomplete backups occupy storage.