How can I create redirects from old URL keys to new ones using a CSV import in Magento 2.3.5-p1?

I have updated the ‘url_key’ column in my Magento CSV file and imported it successfully. However, the old URLs are still returning a 404 error, even though the new URL keys have been updated correctly. On the other hand, when I manually update a product’s URL key in the Magento admin panel, the old URL is redirected to the new one correctly. Can anyone help me understand why the URL redirect is not working after the CSV import?