Box Folder ID (Contact vs. Lead) - Salesforce

Hello,

I created a deeplinks button within Salesforce that utilzies the "Folder_ID" field from the custom Box object called "FRUP" and feeds it into a field within the "Contact" object in Salesforce. I am trying to replicate this, but have it feed onto the "Lead" object within Salesforce and am having trouble. I initially accomplished this through utilizing the "Declarative Lookup Rollup Summary" package. Here is what I did for the contact object and it worked:

I am now trying to do this with the lead object and here is how I set it up: 

This feeds an "ID" into a field on the lead object, but for some reason this ID is twice as long as the ID that fed into the Contact object and doesn't work.

I noticed that there's an additional field on the custom "FRUP" object called "box__Lead_Dest_Folder_ID__c" and I tried swapping this out with the "box__folder__ID__c" field in the "Field to aggregate" section and this caused no ID to map over. 

Please help!

Thanks