Pinterest's policy review flagged products as violating the Merchant Guidelines. Errors 4042 and 4023 block those products from organic and paid distribution, even if the feed itself is technically valid.
Common triggers: claims about health outcomes, weight loss promises, before/after imagery, products perpetually marked as on sale, and products from a website that does not meet Pinterest's quality bar (thin content, missing contact info, broken checkout). Pinterest also blocks merchants whose entire catalog is heavily discounted - it reads as untrustworthy.