Two power query steps dont work together

Additionally - have extracted the SQL sent to Oracle and running it in a standard SQL client returns results just fine:

select "SNAPSHOT_DATE_KEY",
"FINANCIAL_MONTH_KEY",
"LEG_NON_DIR_AIRPORT_PAIR_KEY",
"SUB_ROUTE_KEY",
"OPERATING_AIRLINE_COMPANY_KEY",
"OPERATING_AIRLINE_KEY",
"TICKETING_AIRLINE_KEY",
"ACJ_ORIGIN_DESTINATION_KEY",
"PNR_CREATION_COUNTRY_GROUP_KEY",
"STAR_SERVICE_CLASS_KEY",
"BOOKING_CLASS_KEY",
"RPK_ACTUAL_LY",
"RPK_TY",
"RPK_LY",
"SALES_DEAL_VALUE_ACT_LY",
"SALES_DEAL_VALUE_LY",
"SALES_DEAL_VALUE_TY",
"SALES_REV_PAX_COUNT_ACT_LY",
"SALES_REV_PAX_COUNT_LY",
"SALES_REV_PAX_COUNT_TY",
"REV_PAX_COUNT_ACT_LY",
"REV_PAX_COUNT_LY",
"REV_PAX_COUNT_TY"
from (select "_"."SNAPSHOT_DATE_KEY",
"_"."FINANCIAL_MONTH_KEY",
"_"."LEG_NON_DIR_AIRPORT_PAIR_KEY",
"_"."SUB_ROUTE_KEY",
"_"."OPERATING_AIRLINE_COMPANY_KEY",
"_"."OPERATING_AIRLINE_KEY",
"_"."TICKETING_AIRLINE_KEY",
"_"."ACJ_ORIGIN_DESTINATION_KEY",
"_"."PNR_CREATION_COUNTRY_GROUP_KEY",
"_"."STAR_SERVICE_CLASS_KEY",
"_"."BOOKING_CLASS_KEY",
"_"."RPK_ACTUAL_LY",
"_"."RPK_TY",
"_"."RPK_LY",
"_"."SALES_DEAL_VALUE_ACT_LY",
"_"."SALES_DEAL_VALUE_LY",
"_"."SALES_DEAL_VALUE_TY",
"_"."SALES_REV_PAX_COUNT_ACT_LY",
"_"."SALES_REV_PAX_COUNT_LY",
"_"."SALES_REV_PAX_COUNT_TY",
"_"."REV_PAX_COUNT_ACT_LY",
"_"."REV_PAX_COUNT_LY",
"_"."REV_PAX_COUNT_TY"
from
(
select "rows"."SNAPSHOT_DATE_KEY" as "SNAPSHOT_DATE_KEY",
"rows"."FINANCIAL_MONTH_KEY" as "FINANCIAL_MONTH_KEY",
"rows"."LEG_NON_DIR_AIRPORT_PAIR_KEY" as "LEG_NON_DIR_AIRPORT_PAIR_KEY",
"rows"."SUB_ROUTE_KEY" as "SUB_ROUTE_KEY",
"rows"."OPERATING_AIRLINE_COMPANY_KEY" as "OPERATING_AIRLINE_COMPANY_KEY",
"rows"."OPERATING_AIRLINE_KEY" as "OPERATING_AIRLINE_KEY",
"rows"."TICKETING_AIRLINE_KEY" as "TICKETING_AIRLINE_KEY",
"rows"."ACJ_ORIGIN_DESTINATION_KEY" as "ACJ_ORIGIN_DESTINATION_KEY",
"rows"."PNR_CREATION_COUNTRY_GROUP_KEY" as "PNR_CREATION_COUNTRY_GROUP_KEY",
"rows"."STAR_SERVICE_CLASS_KEY" as "STAR_SERVICE_CLASS_KEY",
"rows"."BOOKING_CLASS_KEY" as "BOOKING_CLASS_KEY",
sum("rows"."RPK_ACTUAL_LY") as "RPK_ACTUAL_LY",
sum("rows"."RPK_TY") as "RPK_TY",
sum("rows"."RPK_LY") as "RPK_LY",
sum("rows"."SALES_DEAL_VALUE_ACT_LY") as "SALES_DEAL_VALUE_ACT_LY",
sum("rows"."SALES_DEAL_VALUE_LY") as "SALES_DEAL_VALUE_LY",
sum("rows"."SALES_DEAL_VALUE_TY") as "SALES_DEAL_VALUE_TY",
sum("rows"."SALES_REV_PAX_COUNT_ACT_LY") as "SALES_REV_PAX_COUNT_ACT_LY",
sum("rows"."SALES_REV_PAX_COUNT_LY") as "SALES_REV_PAX_COUNT_LY",
sum("rows"."SALES_REV_PAX_COUNT_TY") as "SALES_REV_PAX_COUNT_TY",
sum("rows"."REV_PAX_COUNT_ACTUAL_LY") as "REV_PAX_COUNT_ACT_LY",
sum("rows"."REV_PAX_COUNT_LY") as "REV_PAX_COUNT_LY",
sum("rows"."REV_PAX_COUNT_TY") as "REV_PAX_COUNT_TY"
from
(
select "SNAPSHOT_DATE_KEY",
"FINANCIAL_MONTH_KEY",
"LEG_NON_DIR_AIRPORT_PAIR_KEY",
"SUB_ROUTE_KEY",
"OPERATING_AIRLINE_COMPANY_KEY",
"OPERATING_AIRLINE_KEY",
"STAR_SERVICE_CLASS_KEY",
"ACJ_ORIGIN_DESTINATION_KEY",
"PNR_CREATION_COUNTRY_GROUP_KEY",
"BOOKING_CLASS_KEY",
"REV_PAX_COUNT_TY",
"REV_PAX_COUNT_LY",
"REV_PAX_COUNT_ACTUAL_LY",
"RPK_TY",
"RPK_LY",
"RPK_ACTUAL_LY",
"SALES_DEAL_VALUE_TY",
"SALES_DEAL_VALUE_LY",
"SALES_DEAL_VALUE_ACT_LY",
"SALES_REV_PAX_COUNT_TY",
"SALES_REV_PAX_COUNT_LY",
"SALES_REV_PAX_COUNT_ACT_LY",
"TICKETING_AIRLINE_KEY"
from "EDR"."FACT_RES_SUM_AGENT" "$Table"
) "rows"
group by "SNAPSHOT_DATE_KEY",
"FINANCIAL_MONTH_KEY",
"LEG_NON_DIR_AIRPORT_PAIR_KEY",
"SUB_ROUTE_KEY",
"OPERATING_AIRLINE_COMPANY_KEY",
"OPERATING_AIRLINE_KEY",
"TICKETING_AIRLINE_KEY",
"ACJ_ORIGIN_DESTINATION_KEY",
"PNR_CREATION_COUNTRY_GROUP_KEY",
"STAR_SERVICE_CLASS_KEY",
"BOOKING_CLASS_KEY"
) "_"
where ("_"."OPERATING_AIRLINE_KEY" = 226 and "_"."OPERATING_AIRLINE_KEY" is not null)
and "_"."SNAPSHOT_DATE_KEY" >= 20181123 or ("_"."SNAPSHOT_DATE_KEY" <= 20180413 and "_"."SNAPSHOT_DATE_KEY" > 20180316)
and ("_"."OPERATING_AIRLINE_KEY" = 226 and "_"."OPERATING_AIRLINE_KEY" is not null))
"$Paged"
where rownum <= 1000 ;