Check how many videos are tagged to the product
Open the product in your seller dashboard and look at the content count. Zero tagged videos means zero chance. A product that sells consistently usually has a steady flow of new creator videos every week, with a handful driving most of the volume.
Your own account counts. Posting three to five shoppable videos a week from the brand account gives the algorithm something to test and gives creators a format to copy. Brands that post nothing and wait for the affiliate marketplace to work usually wait a long time.
The conversion killers on the product page
Zero reviews stops sales dead. TikTok bans paid or incentivised reviews, so the honest route is a launch price that drives volume plus a card in the parcel asking for a rating. Ratings below roughly 4.5 stars get less exposure in the Shop tab.
Then check the images. The product card shows at thumbnail size in a scrolling feed. If the pack shot has small type, a white background and no context, it disappears. Shoot the product in hand, in use and at a size the viewer can read on a phone.
When the product is the problem
Some products do not work here regardless of execution. Anything that needs explanation, comparison or a considered decision fights the format. Anything over about £60 converts badly without a strong LIVE or a trusted creator. Anything sold cheaper on Amazon loses on the price check.
The products that move have a visible before and after, an immediate demonstration or a strong impulse hook under £30. If you have none of those, either build a bundle that creates one or accept that TikTok Shop is a brand awareness channel for you rather than a revenue line.