[ceph-users] Ceph FS not releasing space after file deletion

Dear ceph users, we are using CEPH since Jewel and now (with Mimic) are facing a problem that is impeding us to use it appropriately. After deleting some big backup files, we have noticed that their space has not returned to the pool's free space. Considering the mentioned pool, du shows that we have a total of 247TB allocated in files and "ceph df" says we have 293TB of used space. How can we debug this problem and force ceph to release unallocated space? Gustavo.