WP_Query not working on Product Search page

Hi. I am experiencing problems using WP_Query on the WooCommerce product search results page. I first noticed it when trying to use the Advanced Custom Field get_field returned an empty array when trying to get a post object. I then tried to manually get the post object but the WP_Query also returns an empty array. It seems there must be some filters being applied to the WP_Query but how do I suppress them? I tried ‘suppress_filters’ in WP_Query but that hasn’t worked. To be clear, it works fine on every other page of the site but not on the product search results page. Any ideas would be gratefully received!

Many thanks