Cypher Query creates a node for every instance of a record (using LOAD CSV)

I'm not sure what the problem is. When I run this query it creates all the date of birth nodes, and then it creates a [WAS_BORN_ON] relationship to every single member for each date. Any help?

LOAD CSV WITH HEADERS FROM "file:///Members.csv" as line 
WITH line 
WHERE line.`Date of Birth`is not null
MATCH (m:Member {whatsappNumber: line.`WhatsApp Number (if different)`})
MERGE (dob: TimeGraph {date: date(line.`Date of Birth`)})
MERGE (m)-[:WAS_BORN_ON]->(dob);

Can you please provide some sample data to see what is happening?

From the query i don't see any issues

Thanks. I found the issue. I had made some changes in excel to the WhatsApp number and it had changed the numbers into scientific notation which was making all my numbers 2300000000.
So when I performed the merge on the dataset, it created the date of birth for each person in the csv.