Rancher 2.5 with ceph rbd storage class

following this forum I was able in the past to connect rancher to an external ceph cluster and use ceph rbd for storage class so I was able to create PVC.
I now am doing the same thing using Rancher 2.5 on a on premise cluster built on ubuntu 20.04
I have reused my yaml configurations but now, even if I reached a point where in “events” I get no errors, I can clearly see that no ceph rbd is created.
Can you tell me how I can debug it deeply?
Is there something different in Rancher 2.5?

Cluster in lxc?

try to search rbd in host /dev