Did you ensure the "Current address (URL)" and "New address (URL)" form fields on the Migrate DB form were filled in correctly?
i.e. the "Current address" field should be prefilled to your current site's current main URL and the "New address" field needs to match your new URL.
Current address (URL) → //exampleold.com
New address (URL) → //examplenew.com
If this looks fine could you try the following:
- Hard refresh your browser's cache
- If using a caching plugin, please clear it's cache
- Save your permalink structure (Settings → Permalinks - Save Changes)
You might also want to double check your wp-config.php to ensure it's pointing to the correct database.
If all else fails, please log into phpMyAdmin, select your new database and click the wp_options table.
The first row should be the
siteurl option, does this contain the old URL or the new one?