Fortigate Hyper-v VM-64 not establish connection BGP.

Hi,

I'm having a problem establishing a BGP connection between the fortiGate VM-64, FortiOS 6 and a Juniper MX router. Both devices have bgp instances configured correctly, but the session is not established. This is true for later versions of FortiOS version 5.2.1. When the downgrade is done for version 5.2.1 the session is established instantly, someone has experienced this problem?

Note: VM Fortigate is hosted on a hyper-v 2016 host.