This is probably a duplicate of an already existing Bug.

CONTROLLER-1751 reports very similar behavior for Nitrogen. Possibly the same bug, but the Robot symptom is different. While on Nitrogen Jolokia works, just reporting cluster is not in sync, on Carbon Jolokia does not find ShardManager [0].

NETCONF-454 is perhaps the same bug, but from its description that looks like a superset of this Bug. According to a comment [1] there, this Bug can be fixed by [2], which is a fix for CONTROLLER-1627.

This Bug is not easy to reproduce reliably, as single restart failure frequency is small. It only affects Netconf suite significantly, because there are multiple restarts.

[0] https://logs.opendaylight.org/releng/jenkins092/netconf-csit-3node-clustering-only-carbon/630/log.html.gz#s1-s5-t13-k2-k2-k8-k1-k2-k1-k1-k3-k1
[1] https://bugs.opendaylight.org/show_bug.cgi?id=8999#c7
[2] https://git.opendaylight.org/gerrit/60485