A listing does not appear in a tag-driven Collection such as Oceanside or Pet-Friendly.
Why this happens. Collections are driven by tags on the listing in your PMS. If a listing has no tags at all, it drops out of every tag-driven Collection.
What to check. Open the listing in Hospitable and verify that all relevant tags are present and formatted correctly, using the tag reference provided at launch. After you save, the site syncs the changes, typically within the hour.