Hello again,
Thank you for getting back. There can be only 2 reasons for a custom post type returning 404.
1. The rewrite rules are not updated which can be updated by navigating to Settings > Permalinks and “Save Changes”.
2. Unpublished posts.
From your description, we’ve run out of both the probable causes. Can you please set your permalinks to default in all the cases and try again? It could be possible that the rewrite rules weren’t generated in the first place.
Thanks,
Ibrahim