SQL: Data Value Revision - sql

Question

I'm trying to pull any ice cream flavors that have a revised flavor_count in our database table. The end result should look something like this:.
Ice_cream_table
I have been working on this code that basically returns all rows (over a million in are DB) incorrectly, and provides the wrong date timestamp:
create table want as (
with temp_tbl as (
select region,report,customer,date,ice_cream_flavor,flavor_count,Order_status,Change_dt
from ice_cream_table
where customer='12345' and Change_dt > to_date(%STR(%'&last_request%'),'DD-MON-YYYY:HH24:MI:SS') and region='south')
select b.region,b.report, b.customer, b.date, b.ice_cream_flavor,
a.flavor_count as "Previous Value",
b.flavor_count as "Current Value",
a.Change_dt as "Previous Date"
from (
select region, report, customer, date, ice_cream_flavor, flavor_count
from temp_tbl
where flavor_status='ACTIVE'
order by ice_cream_flavor
) b inner join
(
select region, report, customer, date, ice_cream_flavor, flavor_count, max(Change_dt) as Change_dt
from temp_tbl
where (flavor_status='Deleted' or flavor_status='Discontinued')
group by region, report, customer, date, ice_cream_flavor, flavor_count
order by ice_cream_flavor) a
on b.ice_cream_flavor=a.ice_cream_flavor
where b.flavor_count<>a.flavor_count /*doing this to provide only changes, not all ice_cream_flavors */
);
quit;
Our data is incremental, meaning revisions become 'discontinued' rows and the latest ice_cream_count is 'active'.
Is there a better way to do this or am I just missing something obvious in the code? Sorry for the long post!