This bug occurs in these Flow actions:
- Sync Lead to SFDC
- Change Owner
In the Assign To field, you can identify the new owner by typing in the name of an SFDC User or an SFDC Queue. This affects only the SFDC User case.
Marketo only lets you select by user name. However, SFDC does not enforce uniqueness for the user name. You can argue whether or not it should -- but the fact is that it doesn't. In addition to simply accommodating large SFDC deployments, there is another use case: SFDC creates user accounts for partner portal users and community users. The same person could thus have multiple "user" accounts, all under the same name. Worse, different people can have "user" accounts under the same name.
When there are multiple names, Marketo simply fails. When I type in a name and see two or more instances, I've tried selecting one to see if at least Marketo can determine with individual account that instance of the name belongs to. But that doesn't work -- it just fails to assign the lead to anyone, and a default has to take over.
It is not practical to try working around this issue by editing the user names to be unique, particularly when the duplicate accounts belong to a partner or community user. Nor can you edit too aggressively a user name, as that can cause issues with reports or integrations involving compensation and the like. Besides, having to edit user names to accommodate this bug is simply not a enterprise-class approach.
The best solution is to enable any Flow action that identifies an SFDC user to do so using something guaranteed to be unique, such as the SFDC user ID.
As already discussed in this thread, , this is more of an idea. here it is: Create a way to differentiate users with the same names for SFDC or MSD assignment