Вы должны переместиться и a.Status = 1 в предложение where:
select Q2.*
from User u,(
select
a.adId as "AdId",
a.UserId as "UserId",
a.Title as "Title",
a.ImageURL as "ImageURL",
a.RefURL as "RefURL",
a.CreateDate as "CreateDate",
a.StartDate as "StartDate",
a.RunTill as "RunTill",
a.Budget as "Budget",
a.Status as "Status",
(a.budget - COALESCE(Q1.A2,0)) as "Remaining"
from Ad a
LEFT JOIN(
select
AdId as A1,
count(*) as A2
from Referral
where date(ReferralDate)=date(CURRENT_TIMESTAMP)
group by AdId
) as Q1
ON a.AdId = Q1.A1
WHERE
a.StartDate<CURRENT_TIMESTAMP
and a.RunTill>CURRENT_TIMESTAMP
and a.Status = 1
) as Q2
where u.Authorized = true
and u.Balance>1
and u.UserId = Q2.UserId
order by Q2.Remaining desc;