Relationship Issue with a Summarized Table

I'm having an issue with a summarized customer table. When I try to relate it to my transaction table by customer number, I get a many-to-many warning. But the summarized customer table only contains distinct customer numbers. The customer number column is also formatted as text. 

When I create a visualization using the customer table, I account 48414 and 000048414 only show once. Needless to say, I am perplexed. I need to create a many to one relationship with my transaction table.