Insert from Influxdb subquery, rows missing and time set to 0

I am inserting rows to a new measurement from a subquery. The subquery returns 2 rows,
but only one is actually inserted to the new measurement.
In addition the time is set to 0, which means I had to set the duration in
RETENTION POLICY “autogen” to before 1.1.1970.

This is the content of StoreSales:

INSERT StoreSales,StoreNumber=“1”,EnteredBy=“Jake”,Month=201906 value=1000
INSERT StoreSales,StoreNumber=“1”,EnteredBy=“Jill”,Month=201906 value=2000
INSERT StoreSales,StoreNumber=“2”,EnteredBy=“Jill”,Month=201905 value=2000
INSERT StoreSales,EnteredBy=“Ann”,Month=201906 value=1000

Set duration to before Unix epoch:

ALTER RETENTION POLICY “autogen” on “DT” duration 450000h0m0s
ALTER RETENTION POLICY “autogen” on “DT” shard duration 450000h0m0s

This is the insert I am trying to use:

SELECT * INTO “StoreSalesByStoreByMonth” FROM ( SELECT Sum(value) FROM “StoreSales” WHERE StoreNumber !=’’ GROUP BY StoreNumber, Month)

The result is:
time written

0 2

But StoreSalesByStoreByMonth only includes one record:

SELECT * FROM “StoreSalesByStoreByMonth”

name: StoreSalesByStoreByMonth
time Month StoreNumber sum

0 201906 “1” 3000

The record for Month=201905, StoreNumber=“2” is missing.
There is on record in StoreSales without StoreNumber on purpose to verify
that the group by excludes the records without that tag.

How can I get all the records from the subquery inserted?
Can I set the time in the query somewhere, so I don’t need to set the RETENTION POLICY “autogen” to before 1.1.1970?