Alexa event arn not tied to alias.

[brettswift]

Expected behaviour:

serverless.yaml

functions:
  mainskill:
    handler: index.handler
    events:
      - alexaSkill:
         appId: amzn1.ask.skill.<skill_id>
https://serverless.com/framework/docs/providers/aws/guide/variables#current-variable-sources

deployed with:

serverless deploy --stage main --alias PROD1 -v

To result in a PROD1 stage, and the alexa event to be joined to it. However this is not the case.

Actual Behaviour

The alexa skill ID is associated to the lambda at the latest version only. This results in an error in the alexa console when I try to add <skill_arn>:PROD1 in the Alexa "Endpoint" because the lambda version does not allow Alexa events.

Am I mis-configuring this or is this a bug?