Paginated ECOM page ranking on Page 1 for competitive keyword instead of primary category

After the recent updates the SERPs seem to be a bit of a mess and Google has me scratching my head! A paginated ECOM page with 1 product is outranking the primary page with 24 products for one of our top keywords for reasons completely unknown! I'm assuming this will just fix itself, but if anyone has any ideas on how to resolve that would be great! Pagination is set up to be crawled and indexed with self referencing canonicals and links from page 1 to page 2 (standard set up) We are also seeing a ton of landing page fluctuation for other keywords when there is no obvious canibalisation! Any one else experiencing this or other anomalies in ecom since the December core and spam updates?