After importing the catalog, go to Sitecore content editor and open the catalog item at this path: /sitecore/content/Sites/<sitename>/Home/Catalogs
, uncheck all the catalogs in the Selected Catalogs
fields and save the item.

Now, From the commerce tab in the ribbon, select refresh commerce cache
, and then select back your imported Catalog at this item (/sitecore/content/Sites/<sitename>/Home/Catalogs
), save the item now.
Few more things to check:
- If you've Sitecore default Storefront website running, then go to this path
/sitecore/content/Sitecore/Storefront/Home/Catalogs
and check Habitab_Master catalog is selected not your imported catalog. You can uncheck the Habitat_Master --> Save --> Reselect Habitat_Master catalog
.
- Go to this item
/sitecore/Commerce/Catalog Management/Catalogs
and uncheck if any catalog is selected and save item.
- Go to this item
/sitecore/Commerce/Commerce Control Panel/Storefront Settings/Storefronts/<Sitename>/Catalog Configuration
and make sure Catalog
should be empty.

- Go to this item
/sitecore/content/Sites/<SiteName>/Settings/Commerce/Catalog Configuration
and make sure your imported catalog is selected.