Short answer
Category, channel links, and what the Listing Tool shows are separate things that do not update automatically. After changing a category in the Catalog, you need to link the products, revise them to eBay, and then use Import → Re-import listing from eBay in the Listing Tool. The full path is Catalog → link → revise → re-import.
First, the important reassurance
If your live eBay listings look correct, nothing is broken. The category names you see in the Listing Tool table are a saved snapshot and are not pulled live from eBay, so they can look out of date until you re-import. Your buyers always see the live eBay listing.
The pieces that don't talk to each other automatically
There are a few separate places that each hold category or connection info, and changing one does not change the others on its own:
The product's category in the Catalog – the folder the product sits in.
The category mapping – the rule that tells us which eBay category to publish to.
The product-to-listing link – whether the Catalog product is connected to its eBay or Shopify listing.
The Listing Tool table – a stored snapshot, refreshed only when you re-import.
Two things surprise people most:
Changing the mapping does not move a product into a different category. The mapping and the product's category are separate settings. If you only change the mapping, the product stays in its original category.
Unlinked products do not receive changes. If a product is unlinked from the channel, revising it will not send anything to eBay. Linking is a manual step (one product or in bulk); it does not happen automatically.
How to fix it (bulk)
Everything below is in the Catalog, under Bulk Actions, except the final step. Select the products you want to update first.
Bulk Actions → Edit Product Categories – set the correct category on the selected products.
Bulk Actions → Link/Unlink Products from Listings – make sure the products are linked to the channel. Changes will not reach eBay while a product is unlinked, so do this before revising.
Bulk Actions → Revise Product Listings – this pushes the changes out to eBay.
In the Listing Tool, click Import → Re-import listing from eBay – this refreshes the Listing Tool table so the categories display correctly.
For a single product
The same order applies: set the category on the product, confirm it is linked to the channel, revise it, then use Import → Re-import listing from eBay in the Listing Tool.
How to avoid this going forward
Set the category on the product itself, not just the mapping.
Keep products linked to their channel.
Remember the Listing Tool table is a snapshot – after any Catalog change, revise and then re-import so it catches up.
None of these steps are automatic, so make link → revise → re-import your habit after category changes.