Starting on the first of March this year, page feeds for Dynamic Search Ads will no longer be able to contain multiple items with the same URL. The URL will be treated as a unique key and for this reason, the same URL can’t be applied to more than one item.
From the first you will receive an error if you attempt to add a new feed item using the same URL as an existing item. On the 29th March 2021, all items which are disapproved because of duplicate URLs will be deleted.
Now is the time to review your feed and ensure you aren’t using duplicate URLs. This will prevent any issues when this new policy comes into place in March.