Why No shard becomes primary on second node when it is UP again?

I have configured two node cluster and created an index with 4 shards and 1 replica

Elastic created 2 primary shards on each node, this is how it looks from head plugin. shard 1, shard 3 are primary on node 1(stephen1c7) AND shard 0 and shard 2 are primary on node 2(stephen2c7)

Shutdown one Node

Now i have shutdown the node 2(stephen2c7) to see if all the shards on node 1(stephen1c7) became primary. Yes, all shards are now primary.

UP the shutdown node

Now i have made the Node 2(stephen2c7) up again to see if any shards on this node will be primary. But surprisingly no shard on this node became primary. Waited for long time but still no shard is primary on Node 2. Why so?

Is there any configuration to set for making the shards primary again after a node is up?

Thanks in advance!