Hello Zangirolami,
I've responded to your message a week ago, but it seems that it wasn't delivered, anyway, Yes, I've solved the issue.
it's all about the sorting of LUNs and the LUN ID, you know, when you assign a LUN to a server it gets an ID on that server, so, in the case of a shared LUN/datastore, it must be with the same LUN ID across all hosts sharing that LUN, meaning, if the shared LUN ID is "5" on a host, all of the other hosts that share the same lun must have it with the same ID "5".
the LUN get's the ID when it's assigned to a server from the SAN side, so keep the LUN ID the same and your issue will be solved, it's all about the LUN signature, when the LUN ID is the same, the signature is the same, if the ID differs across the hosts, the signature will also be different and it will be required to format it from one or more hosts to be able to access it.