Amazon Posts Algorithm and Post Feed Categories

I’ve been doing regular Amazon posts for the past few months and I still can’t work out how the algorithm/Amazon decides on the post’s feed categories that are below the caption. I’ve tried adding words from the post feed categories to the caption to go into that category e.g. adding “garage” and “storage” so the post is tagged in the “Garage Storage and Organization” feed category but it’s random. Also all the products I list in the posts are the same and belong to the same product category in Amazon. Anyone have any experience with controlling the Post Feed Categories that appear under Amazon Posts, or have any other Amazon Post tips?