Fix counting query in "Data in Helmholtz"

While checking the data presented on the updated dashboard (subpage "Data in Helmholtz") shows "no data publications found" when filtering for "GEOMAR".

In contrast, the following SQL Query provides >919 data publications.

Please review the sql query and fix this bug. Thanks :-)

SELECT 
DISTINCT pdat.id
FROM publication AS plit
INNER JOIN reference AS ref ON plit.id = ref.reference_id 
INNER JOIN publication AS pdat ON pdat.id = ref.reference_to_id 
INNER JOIN center_has_publication AS cp ON plit.id = cp.publication_id 
INNER JOIN center AS c ON cp.center_id = c.id
WHERE c.name = "GEOMAR" AND ref.sub_type = "IsSupplementedBy";