My Synology DS220 says i already used 3.2 TB out of my 3.5 TB storage but in fact we only use 700GB yet

Synology DiskStation DS923+ NAS Server with Ryzen 2.6GHz CPU, 32GB Memory, 16TB SSD Storage, 1TB M.2 NVMe SSD, 2 x 1GbE LAN Ports, DSM Operating System : Electronics

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Synology DS220+ 2-bay USB3 Reviews, Pros and Cons

DSM shows disk are 34% full but it also tells me that they are totally full and i can no longer to DSM

Synology 2-Bay DiskStation DS723+ (Diskless) & M.2 2280 NVMe SSD SNV3410 800GB : Electronics

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Synology DS223j NAS Revealed – The BEST Value Entry into DSM 7.2? – NAS Compares