Summary

Apart from using the default environment name, custom environment names can also be used in the .yml file on GitHub. However, on JIRA Releases panel they don't show correctly and instead, we see "Undefined Environment". 

Environment

• Jira Cloud
• Github Cloud

Diagnosis

• To use custom environment names in Github deployments, the names must be defined in the config.yml file as noted in this document - Github Deployments in JIRA
  
  
• If this is followed correctly, the custom names show up as expected in the "Deployment" section on the Jira tickets as shown in the below screenshot:

• However, the Releases section shows the environment as undefined.
• Re-synching the GitHub Organisation (all repositories) does not work.

Solution

After the config.yml file is created for the first time, the GitHub connection needs to be disconnected and reconnected with JIRA cloud. Post that, any further changes made to the config.yml file will be picked automatically.