Why does my new Additional Information field become the first Custom Field/Custom Value column pair in my contact CSV file?
In your organization Settings > Organization > Contacts/Assets > Additional Information, you can add Additional Information fields for contacts. For a thorough explanation of how to do this, please see article 2688 - How to Configure Additional Information Fields for Contacts in Everbridge Suite.
When you add a new Additional Information field, it will appear at the bottom of the Additional Information list in contact records. For example, in the screenshot below, "Location" was the most recently added Additional Information field, and it is at the bottom of the list.
However, when you add this new Additional Information field to a contact record and download your contacts in a CSV file, you will see the new Additional Information appear as the first Custom Field/Custom Value column pair, not the last.
This does not have any impact on your uploads, as custom fields do not need to be in any specific order. The system checks every custom field and custom value, and if they match an Additional Information field, they will upload the information regardless of the column order in the CSV file.
For a thorough explanation of how to configure you contacts' Additional Information fields via CSV file upload, please see article 57505 - How to Configure Additional Information Fields for Contacts via CSV File Upload to Everbridge Suite.