In most cases, the eSIM can only be activated/started when you have arrived at your destination. If you have not arrived at your destination, then it is normal to see that your eSIM has not been activated/started, even if you have completed your installation process.
For more information on how to activate/start your eSIM, please refer to this article.
The eSIM status can sometimes take a few minutes to update on your Nomad app. If you are already at your destination, your eSIM is turned on, and data roaming is turned on, but your Nomad app still shows that the eSIM is not activated, please refresh your Manage page and check again in a few minutes.