Multicast packets fail to pass through when the next hop route uses a VIP IP in the following configuration:
Rendez-vous point IP config:
ip pim rp-address 172.30.16.222
Default route config in XOS for the affected VAP group:
ip route 0.0.0.0/0 172.31.67.10 vap-group <VAPname> circuit <circuit name>
PIM debug showing a similar output:
PIM-SM: MRIB.next_hop_rp(172.30.16.222): nexthop 172.31.67.10
PIM-SM: US (*,G): No RPF neighbor for (*, 188.8.131.52)
The default gateway address 172.31.67.10 is likely not a direct PIM neighbor, but a virtual IP address (VRRP/HSRP/GLBP).
The PIM neighbors must use a physical interface IP, not a virtual IP address.
Have a more specific route(s) to the rendez-vous point IP address than a default route.
In this case, you may need to add multiple static routes to ensure redundancy for unicast traffic.
# configure ip route 172.30.16.222/32 <nexthop1> vap-group <VAPname>
# configure ip route 172.30.16.222/32 <nexthop2> vap-group <VAPname>