Disable VDOM Link Interface with Link-Monitor

Hi,

First, the platform is FG200D running FortiOS v5.4.6

In my firewall config I have VDOM A and VDOM B, which are interconnected using a virtual VDOM Link.  There's a static route in VDOM A which points to VDOM B to get to a distant host.  I'd like to control whether the static route exists in VDOM A based on the reachability of an intermediate IP past VDOM B. 

So, I configured a link-monitor setting the "srcintf" to the VDOM Link and the "server" to the intermediate IP.  When I test this however, the link-monitor does not bring down the VDOM Link when the intermediate IP is unreachable.  

Has anyone tried this before?  Alternative suggestions?

Thanks for your time.

Lar