The existing system and multinode tests:

AT_SETUP([ovn multinode bgp L3 EVPN]) 

and

AT_SETUP([dynamic-routing - EVPN]) 

don't ensure that NAT's configured on OVN logical routers that have 

dynamic-routing-redistribute=nat|lb 

configured are advertised as Type5 EVPN routes (IP routes).

The tests should be updated to do that and the multinode test should also ensure that traffic from the fabric towards the Type5 EVPN targets is properly forwarded to the OVN workload running behind the NATs.