To update a synced registry from a desktop or laptop: 

1. Hover over THINGS TO DO 
2. Select Sync/link store registries
3. Hover over the registry you would like updated
4. Click UPDATE AND RE-SYNC from the logo of the store you would like updated.

To update a synced registry from the mobile app: 

1. Select the MENU icon located on the bottom of the panel
2. Scroll down to click Things to do
3. Select Sync Store Gift Lists
4. Click on the registry you would like updated and select UPDATE AND RE-SYNC REGISTRY.