You should only use Change Owner or Sync Lead to SFDC: Queue with Marketo only or SFDC Type=Lead or IS EMPTY (Marketo only).
Syncing SFDC Contacts to a Q causes duplicates.
Now, for your specific error, what do the logs say in both systems? Is there a Lead Assignment Rule (LAR) that overrides?
Below is our Lead Assignment Rule for SFDC.
(Lead: Campaign Member StatusEQUALSResponded) OR (Lead: URL MediumEQUALSPPC) OR (Lead: URL SourceEQUALSAdwords) OR (Lead: Lead Source DetailEQUALSContact Us Page) OR (Lead: URL MediumCONTAINSRemarketing)
I have attached the flow for this specific smart campaign in Marketo.
You lost me with the "Sync Lead to SFDC: Queue with Marketo only or SFDC Type=Lead or IS EMPTY (Marketo only)."
So what you are telling SFDC here is
- Insert Lead into SFDC and make the Queue the Owner.
- Right after that, you are asking SFDC to Add to SFDC Campaign
- At that moment, SFDC says "Oh, you have a Responded Member, I'll do XYZ with them"
So I'd recommend that you modify your LARs to do what you want and then Adding to SFDC Campaign as Responded will work.
Also, keep in mind that you are running TWO syncs in this screenshot. It's more efficient to let the LARs assign the Lead and then just use Add to SFDC Campaign.