One out of five hosts not VCD-NI capable in vCloud Director

I'm running a resource pod with five ESXi 5.5.0 (2718055) hosts. The PvDC uses a VXLAN network pool with an underlying dedicated VLAN, MTU on VMKNics and physical switches is 9000.

vShield Manager shows "Ready" for the cluster's network preparation. vCloud Director (5.6.4) shows a green check mark for four of the hosts but not for the most recently added one.

I already unprepared and reprepared the host in vCloud Director.

Any ideas what's missing here?