When I Create Release and click on Save, it automatically deploys the package before hitting on the Deploy button, and when I click on Deploy it deployed the same package again.
Could you please check the Lifecycle associated with that Project/Channel and see if there is a lightning bolt icon next to the Environment being deployed to?
Here is an example:
If there is, the reason the release is being automatically deployed is that it has been set to automatic deployment. To change this you will need to go to the phase within the lifecycle, delete the environment, and re-add it selecting manual deployment.
Please let me know if that resolved it for you or if you potentially have another issue causing this.