This issue has been mitigated and Salesforce integration service is now functioning properly. We are monitoring this issue to ensure stability. If you have any additional questions, please contact Marketo Customer Support at https://support.marketo.com.
Posted 17 days ago. Apr 09, 2018 - 22:16 PDT
A small subset of Sydney customers have reported problems related to Marketo integration with Salesforce. We are actively investigating this issue now and will post updates as soon as they become available.