Etsy turned away a stock update for this listing. The listing uses Etsy's Global pricing together with a variation type picked from Etsy's list, and Etsy does not let any app update those listings yet.
Why it happens
The listing has Global pricing turned on. Global pricing lets you set separate prices for domestic and international buyers. Check the listing's price settings in your Etsy account.
Its variations use a type from Etsy's list. Etsy offers ready-made variation types, such as Primary color or Ring size. Check the listing's variations in your Etsy account.
When both are true, Etsy blocks the listing's stock, prices and SKUs. If you run a full product update, the update stops at that step, so images, videos, attributes and personalization in the same update are skipped too. Titles, descriptions and tags are saved before that step, and orders still transfer to Shopify.
Listings with Global pricing whose variations you named yourself keep syncing, and so do listings without variations.
How to fix it
In your Etsy account, open the listing.
Do one of these:
Switch the listing to a single price in its price settings.
Keep Global pricing, and replace each variation type from Etsy's list with a custom variation you name yourself.
Save the listing on Etsy.
Shuttle syncs the listing's stock again at the next update.
If you want to keep the listing as it is, manage its stock yourself in your Etsy account. When Etsy adds support for these listings, Shuttle syncs them again with nothing to change on your end.
To see which listings are affected, open Stock Syncer in Shuttle. Affected listings show "Stock update blocked" in the sync history.
Still seeing it?
If you changed the listing to a single price or to custom variations and its stock updates are still blocked, contact Shuttle support and tell us which listing it is.