Connection ESXi 6.7 RPN SAN



I have an ESXi 6.0 server connected to 2 RPN SAN disks, via RPNv1. These disks are used to store backup data.
I have also a new ESXi 6.5 server, to replace the old ESXi 6.0 server.
I would like to connect my new ESXi 6.5 server to RPN SAN disks.
I followed this tutorial :
I configured compatibility with RPNv2 - RPNv1.

My configuration is :
On ESXi 6.0, I have a Windows VM connected to RPNv1. IP VM 10.91.x.x.
On ESXi 6.5, I created a Windows VM. IP VM 10.88.x.x.

Ping from 10.91.x.x to 10.88.x.x succeded.
Ping from 10.88.x.x to 10.91.x.x failed (request timeout).

I have pfSense on both ESXi.

Can anyone help please ?