Compact command is not reclaiming any space

I am using MongoDB 4.2 community edition and working on 3 node ReplicaSet (PSS).
each node is 10 cores, 42 GB and 5.5TB of storage space.
I have deleted almost 900GB of data as I can see it in file bytes available for reuse in db.collections.stats()
Issue is compact command is not reclaiming space. I have ran it 6-7 times.
In past also I faced this issue, but compact used to free up some space in 2nd or 3rd attempt. But this time after running for 2 hours it just throws (ok,1) but without gaining any space.
Can anyone please help me in this regards ?