Finale is configured to update all marketplaces within 5 minutes of a change in stock levels. Although we push this to every marketplace, not every marketplace processes the feed in the same way.
One problematic marketplace is Walmart. Unfortunately due to limitations with how Walmart processes their API feeds (not just from us, from all software that communicates to their platform), at various times throughout the day, the process can get bottlenecked.
Due to the way Walmart processes feeds in a first come-first served order, once the API feed gets backed up, it'll continue to get backed up until either the volume of API feeds lowers, or they wipe the queue and accept new feeds.
We do not have any control over this, unfortunately. When we push an update to a listing in Walmart, we wait for a response from the server that it was processed successfully. If the maximum wait time is exceeded before we receive a positive response, then we assume that the feed was not processed and terminate the process in Finale (logging an error on the integration). We then queue up every product that was on that feed to be updated again, and continue to try over and over until we receive a positive response that the feed was received.
To read more information regarding Walmart's official feed processing time, please visit the developer documentation on Walmart's website.