Why can't I use Cloud IDE with my multisite setup?
Cloud IDE fully supports Drupal multisite applications (https://docs.acquia.com/ide/faq/#can-i-run-a-multisite-application-on-cloud-ide), but it must be noted that the IDE does not recognize multisite directory structure. The only directory the Cloud IDE will use is
/sites/default, so if you need to make changes to
services.yml for any other sites, you will need to change it in
/sites/default as well.