Would appear to be some kind of bug since your CoreXL split is identical on both members. However do you have another separate ClusterXL cluster running R80.10 or earlier on the same VLAN(s) as the problematic cluster? Wondering if it could be a Magic MAC issue with an older cluster present, as Automatic MAC Magic was not introduced until R80.20. Make sure that Automatic MAC Magic is enabled on all your clusters that support it with this clish command: show cluster mmagic
Also:
Cluster failover count:
Failover counter: 3007
Your cluster is flapping like crazy, TAC should probably be engaged here to see what is happening.
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