It's not possible to log in to Mailchimp in Supermetrics with multiple accounts. This is because there's no way for the system to identify the account that built the report, so MailChimp returns results with the next refreshes from any of the accounts that you have access to at random.
There is a workaround for this limitation.
To fix this, please assign unique email addresses to each business account. This means you should log in with a different email address for each business account. To add a new user, follow these steps:
- Authenticate Mailchimp in Google Sheets.
- Under Data source, click the chevron next to the data source's name.
- Click Add new user.
- Follow these instructions and navigate to the tab Multiple users.