Ansible Yum Update

Hi Guys,

I have been using ansible for 3 months now and I updated my servers’ packages using yum module.
My goal is to update all the packages in those servers to latest. The command line will be “yum -y update”
As stated in ansible document for yum: https://docs.ansible.com/ansible/latest/collections/ansible/builtin/yum_module.html#parameter-name

My playbook looks exactly like following:

I found that it updates my OS too. As a result, some of my services which have version dependencies stopped working.
Where did I go wrong? Please kindly help explain.