Good to know that you have created a cluster. 
Resize issue is a known issue for beta. CSE polls the RDE at regular interval to pickup any change.
You may check using https://{{base_url}}/cloudapi/1.0.0/entities/types/vmware/capvcdCluster/1.1.0 to see the RDE got updated : entity->spec->capiYaml has got the updated replicas for worker node.