@ChrisRose  to add to whatever has been said, nondeterministic ordering seems to be reason. You can check using this query : 

SELECT
customer_name,
DATE(submitted),
COUNT(*)
FROM your_view
GROUP BY customer_name, DATE(submitted)
HAVING COUNT(*) > 1

If the earliest submitted date for that customer_name has customer_id = NULL, then SQL editor/notebook may appear correct, hwoever since job runs show full data if the first row is NULL, result is also NULL.

You can confirm using this query:

SELECT
customer_name,
submitted,
Customer_ID
FROM your_view
WHERE customer_name = '<problem_customer>'
ORDER BY DATE(submitted) ASC

Additionally to resolve this you can add a tie breaker to the query as given below:

FIRST_VALUE(Customer_ID IGNORE NULLS)
OVER (
PARTITION BY customer_name
ORDER BY DATE(submitted) ASC, submitted ASC, record_id ASC
) AS Customer_ID