Why Leader is rotating after every block creation in Hyperledger fabric SBFT 2.3.0 #fabric-orderer #consensus


We are using Hyperledger Fabric 2.3.0 and using SBFT Consensus,
and leader is rotating after every block creation.
and we set MaxMessageCount to 10 in configtx.yaml but it is not restricting no of transactions in a block to 10 rather it is accumulating random number of transactions .
How can we configure batch size in SBFT. any suggestions.