I am busy building a multi-step welcome journey in SFMC, but some aspects aren't working as expected.
We have an external CRM system that we import data from in to SFMC, where our ConsumerID is set as the SubscriberKey.
I have an automation that selects all new Consumers (based on acquisition date in our CRM) and places them in to a DE that is the source for my journey. That DE is set up in Contact Builder with Contact Key linked to ConsumerID.
I have created a number of DEs to log Consumers that enter and exit the journey (using the Update Contact Event in Journey Builder). These log DEs are set up in Contact Builder as Attribute Groups, and linked to the Contact Key.
The Update Contact Event is configured to update the 'Send_Date' field in my Log DEs, with 'use current date'.
However, when the Update Contact Event triggers, it is loading the email address in to the Log DE, not the ConsumerID.
Contact Builder is a bit confusing, so I am guessing I have set something up incorrectly, but I have no idea what, any ideas?