If you see customers present in the 'No Tier Assigned' bucket in the Data Sync tab, follow these steps to resolve.
CRM is synced
If you've synced your CRM to Staircase (Salesforce, Hubspot) and mapped your tiers, a missing tier means that the tier is not defined on your CRM. As soon as you set the tier for this account on your CRM, it will flow into Staircase and resolve this data sync issue.
CRM is not synced
If you are manually adding customers one-by-one or via the bulk upload, please update the tier value for those missing in your bulk upload file and send to your Staircase CSM or log into Staircase, search for the customer name from the Customer Overview table, scroll to the right in the table, click the pencil symbol, assign the owner, and click update.