Sequence of events

• initial view: node-2, node-3, node-5
• node-2 left the cluster
• node-6 joins the cluster during state transfer between node-3 and node-5

From the quick analysis, state transfer is in progress between node-5 and node-3 when node-6 joins. A new state transfer is queued as expected. For some reason, node-3 internal state is getting corrupted based on the following log entry

ISPN000396: Received unsolicited state from node node-5 for segment 20 of cache offlineSessions

The current state transfer never finishes wich prevents node-6 to join the cluster and fails with timeout waiting for state transfer error.