Your source feed updates on a schedule, just like each of your channels. To exit that schedule and update immediately, you must Force Update your Source Feed from your Source Feed Page. You will receive a notification once your source feed has completed updating.
Once your source feed is updated, you will find your new products, waiting to be submitted, in each of your channels. You can force the update of each channel manually with the Update button found on the top bar of each channel.
NOTE: once you have your channel configured, to ensure new products successfully list, make sure you have configured the new products similar to the existing products in your store.
How fast the newly added products will show up on my sales channels?
