Salesforce Hubspot integration set up

We are collecting leads through a form with less than 10 fields on a landing page on Hubspot. Those leads must pass through a workflow to complete the process of filling some fields that Salesforce requires such as lead_owner. Hubspot offers a synchronization interface with Salesforce to set up the field mapping. The mapping is already done but still continues showing synchronization errors. We need to fix this integration by setting up a proper configuration on Hubspot. No coding needed.
Form is already created
Landing page is already created
Workflow is already create
Mapping is already done