This is not a problem when the CA is the only connected node in the cluster. To reproduce this, create an external RA setup with an outgoing peer connector from the CA to the RA.

public PeerMessage responseFromMasterHandOff(final PeerRaSlaveMessage peerRaSlaveMessage) {
...
    final int apiVersion = peerRaSlaveMessage.getApiVersion();
    if (lowestConnectedApiVersion>apiVersion) {
        // Older CA has reconnected after downtime
        lowestConnectedApiVersion = apiVersion;
        lowestConnectedApiVersionConnectTime = start;
...
}

peerRaSlaveMessage.getApiVersion() frequently incorrectly returns 0, even though the lowest connected API version has a higher API version. This makes lowestConnectedApiVersion constantly being set to 0.

In turn, the method getApiVersion() in RaMasterApiProxyBean returns 0 for all the nodes in the cluster which disables features which requires a higher API version (for example RA Web end entity status change, see ECA-6433).