Question:

There is an active Related to Top Level VMOC Type for Contract Partner Object with Include Attachments checked. However, attachments are not synced down to the user's device offline. Why does this happen?

Answer:

Currently, this is working as designed. Related to Top Level VMOC types, runs a subquery to get associated records to parent records, this would not sync down attachments. To sync attachments use Full or Top Level VMOC types for Contract Partner Object.

Related Documentation:

CRM Help Documentation: Using VMobile Object Configurations