The multicast is bound every time to eth0, even though route -n says it should be routed to eth1.
This is the snippet of the route:
224.0.0.0 0.0.0.0 248.0.0.0 U 0 0 0 eth0
232.0.0.0 0.0.0.0 248.0.0.0 U 0 0 0 eth1

So this multicast address 232.1.90.52 should be routed to eth1 and 224.1.90.52 to eth0, but as the tcpdump output snippets shows, it is routed via eth0, regardless on the address.

listening on eth0, link-type EN10MB (Ethernet), capture size 65535 bytes
07:37:36.516628 IP perf19.mw.lab.eng.bos.redhat.com.45688 > 232.2.90.52.45688: UDP, length 92
08:58:31.352847 IP perf19.mw.lab.eng.bos.redhat.com.45688 > 224.2.90.52.45688: UDP, length 92

The bind address of the AS is on eth0, perhaps it can be related to each other?

Seen this issue with EAP, maybe this is present also in AS, but I did not investigated it.