I believe the cause of this issue is the fact that you have no locations selected for Linnworks to send the stock levels from to the channel.
I have attached an image showing where you can enable a location to update you stock from. Once you enable a location, Linnworks will try sending the stock levels on the next sync.
Tech Support Team
Linnworks is not updating /syncing inventory on amazon. I have rechecked Amazon is properly integrated and inventory sync is enabled. I also recheck the listing is also properly mapped but still no luck.
Appreciate if someone can help me resolve this issue.