1. setup a redis cluster with 3 master serving slots [0-5460], [5461-10922], [10923-16383], called it M1, M2, M3.
2. use redis-cli to execute "ssubscribe" on channel CH0 with slot 0 on slave serving slot [0-5460], called it S1, so that we are subscribing CH0 on S1.
3. execute CLUSTER REPLICATE on slave S1 to replicate M2, so that it becomes S2, replicating slot [5461-10922], and no longer replicate [0-5460]
4. redis-cli does not receive sunsubscribe or any signals on CH0 and continues to block.

Is this a bug?