Vlan interfaces on multiple VDOMS

Hi, I am using Multi vdom setup on my Firewall, on the 2nd VDOM I have noticed when I have created the 2nd virtual interface vlan on the new VDOM on the same physical  internal ports as the 1st vdom, I notice the physical ports are greyed out on the 2nd vdom, but green on the 1st vdom. These new virtual interfaces are assigned to the new vdom fine but why are the physical ports greyed out on the 2nd vdom? I manged to establish the BGP neighbors in these new vlan interfaces fine. If I view the Global config on these physical interfaces I see the 1st vdom is configured under the physical interfaces, you cannot assign multi vdoms in the global vdom.