Hi i can also confirm that by activating NextGEN 2.0.0 the tickets disappear.
Enabling debugging produces this SQL statement.
WordPress database error: [Unknown column ‘ids’ in ‘field list’]
SELECT DISTINCT ids FROM wp_posts INNER JOIN wp_postmeta ON (wp_posts.ID = wp_postmeta.post_id) WHERE 1=1 AND wp_posts.post_type = ‘product’ AND (wp_posts.post_status = ‘publish’) AND ( (wp_postmeta.meta_key = ‘_tribe_wooticket_for_event’ AND CAST(wp_postmeta.meta_value AS CHAR) = ‘159’) ) GROUP BY wp_posts.ID ORDER BY wp_posts.post_date DESC
This happens on the events page both in the front and backend.
Deactivating NextGEN fixes the issue.