Source Campaign field is not updating in Dynamics from Marketo

The Source Campaign field in Microsoft Dynamics is not getting updated when the field is updated in Marketo.

The sync from Microsoft Dynamics to Marketo will be working fine.

Native integration with Microsoft Dynamics
Campaign Sync not Enabled

To sync Campaign Source from Marketo to Dynamics, the option 'Campaign Sync' needs to be enabled as per this documentation: Enable Campaign Sync | Adobe Marketo

If the Campaign Sync is not enabled we will not be syncing over the value of the field to Microsoft Dynamics as it is part of the Campaign Sync.