Database Error when used with Show Single Variations

There appears to be a compatibility issue with the Relevanssi search plugin and the Show Single Variations plugin. https://iconicwp.com/products/woocommerce-show-single-variations/

When Show Single Variations is active, Relevanssi no longer works. It produces a database error with the following query

SELECT COUNT(DISTINCT(relevanssi.doc))
FROM ***_relevanssi AS relevanssi
WHERE relevanssi.term = ‘*******’
AND relevanssi.doc NOT IN (
SELECT DISTINCT(tr.object_id)
FROM ***_term_relationships AS tr
WHERE tr.term_taxonomy_id IN (6,9))
AND relevanssi.doc NOT IN (
SELECT DISTINCT(tr.object_id)
FROM ***_term_relationships AS tr
WHERE tr.term_taxonomy_id IN (498))
AND relevanssi.doc NOT IN (SELECT ID
FROM ***_posts
WHERE post_parent IN ())
AND ( relevanssi.doc IN (
SELECT DISTINCT(posts.ID)
FROM ***_posts AS posts
WHERE posts.post_type IN (‘product’, ‘product_variation’) ) )

With the following error message

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ‘)) AND ( relevanssi.doc IN ( SELECT DISTINCT(posts.ID) FROM ***_posts AS ‘ at line 8

With the Show Single Variation plugin deactivated Relevanssi works as expected.

I have also sent this error report to the IconicWP developers incase its an issue on their end.

Any further info needed please let me know.

Thanks,

James