Your Salesforce sync cycle is taking longer than usual. How long is too long?
By default, Marketo starts each Salesforce sync cycle five minutes after the previous cycle completes. Each sync cycle may take a couple of minutes or a couple of hours, depending on how much data needs to be written across. If you notice your sync cycles seem to be taking longer than usual, here are some things to check.
Have you done a large update recently? This can create a backlog that can take time to work through.
Have you added new fields to any of your synced Salesforce objects? The more fields on the object, the more data needs to be written across, extending the sync cycle.
If you would like to streamline your Salesforce sync, do an audit in Salesforce of fields visible to the Marketo Sync User. If there are any fields that are not used in Marketo, remove visibility to them so Marketo does not waste time syncing them.