BGP FlowSpec not advertising route

I've enabled BGP FlowSpec to an IOS XR peer but I'm not seeing any FlowSpec routes being advertised.

I've used the APP RIB to add a flow-spec route:

<flowspec-route xmlns="urn:opendaylight:params:xml:ns:yang:bgp-flowspec">
<route-key>foo</route-key>
<flowspec>
<component-type>destination-port</component-type>
<destination-ports>
<op>equals</op>
<value>8080</value>
</destination-ports>
</flowspec>
<attributes>
<origin>
<value>igp</value>
</origin>
<as-path/>
<local-pref>
<pref>100</pref>
</local-pref>
<extended-communities>
<comm-type>128</comm-type>
<comm-sub-type>7</comm-sub-type>
</extended-communities>
</attributes>
</flowspec-route>

The route appears in the LocRib and in the peer's AdjRibOut but is never advertised to the peer.

Of course the route may be incorrect

The peer runs eBGP and is in AS65504. ODL is in 64496.

Giles