Hyper-V - S2D - Deduplication

Question

Hi community

I'm using an S2D cluster with cluster shared volumes for hosting my virtual machines.
On one volume I'm hosting an vhdx file which contains only file server data.

On the virtual machine I enabled the deduplication, so my VHDX is well deduplicated, but on the Hyer-V, I also enabled the deduplication on the CSV volume.

My deduplication is stuck to 0% and I don't know why.

I was wondering if it is necessary to enable the deduplication on the 2 volumes (the CSV and inside the VHDX).

I suppose the deduplication inside the CSV is the only one I need to enable ?

thanks