I am using the yum module to lock the release version for a RHEL 7.6 machine to 7.7 version. However the yum --releasever option does not set the release version to 7.7. I am using Ansible 2.7.10 version.
Here is the discussion regarding the issue: 
https://access.redhat.com/discussions/4774501

ISSUE TYPE
Bug Report

COMPONENT NAME
yum --releasever

ANSIBLE VERSION
2.7.10 

STEPS TO REPRODUCE
name: installing updated packages
yum:
name: '*'
state: latest
releasever: '7.7'

ACTUAL RESULTS
Play runs successfully however it does not update the release version of the server
state: latest
- name: upgrade all packages, excluding kernel & foo related packages
  yum:
    name: '*'
    state: latest
    exclude: kernel*,foo*
- name: install the nginx rpm from a remote repo
  yum:
    name: http://nginx.org/packages/centos/6/noarch/RPMS/nginx-release-centos-6-0.el6.ngx.noarch.rpm
    state: present
- name: install nginx rpm from a local file
  yum:
    name: /usr/local/src/nginx-release-centos-6-0.el6.ngx.noarch.rpm
    state: present
- name: install the 'Development tools' package group
  yum:
    name: "@Development tools"
    state: present
- name: install the 'Gnome desktop' environment group
  yum:
    name: "@^gnome-desktop-environment"
    state: present
- name: List ansible packages and register result to print with debug later.
  yum:
    list: ansible
  register: result
- name: Install package with multiple repos enabled
  yum:
    name: sos
    enablerepo: "epel,ol7_latest"