unity 350F with vmware compressed datastores

i'm using 350F solely for vmware vsphere 7 and the datastores are compressed

now i'm unable to use the full potential of the compressed datastore

that is, i'm running at 2:1 data reduction, my raw capacity is 2.5TB but i can only use 1.25TB of raw data since vsphere 7 sees the disk as begin 100% full...

so what is the point of having compression if vsphere can't handle it?

or what am i doing wrong? i don't see any setting in vsphere 7 that could solve this...