SQL Query produces duplicates with "Where IN" query - sql-server

Question

I have a large SQL statement which does a whole load of joins on my tables. I have converted some of my table relationships to many-to-many relationships so that it is more efficient. I have therefore decided to convert my SQL to do a WHERE IN statement (on location).
The following query is the one that currently returns the desired results:
ALTER PROCEDURE [dbo].[GetMemberListing]
#Locations nvarchar(max)
AS
BEGIN
-- SET NOCOUNT ON added to prevent extra result sets from
-- interfering with SELECT statements.
SET NOCOUNT ON;
select
Member.Id,
AspNetUsers.Salutation,
AspNetUsers.FirstName,
AspNetUsers.PhotoUrl,
AspNetUsers.LastName,
AspNetUsers.Birthday,
AspNetUsers.Gender,
Member.IDType,
Member.JoinDate,
CONCAT (AspNetUsers.FirstName, ' ', AspNetUsers.LastName) as FullName,
AspNetUsers.CountryCode,
AspNetUsers.Email,
Location.Name as LocationName,
AspNetUsers.HomePhone as HomePhone,
coalesce(Package.Name,'No Package') as PackageName,
PackageTerm = case when Package.PackageIsReoccuring = 1 then 'Recurring' when Package.PackageIsSession = 1 then 'Paid In Full' when membership.TotalPrice = 0 then 'Free' when Package.PackagePayInFull = 1 then 'Paid In Full' end,
PackageType.Name as PackageType,
MembershipId = case when membership.id IS NULL THEN '' ELSE 0 end,
coalesce(membershipstate.name, 'N/A') as MembershipState,
MembershipStartDate = case when membership.StartDate IS NULL THEN '' ELSE CONVERT(varchar(50),membership.StartDate) end,
MembershipEndDate = case when membership.EndDate IS NULL THEN '' ELSE CONVERT(varchar(50),membership.EndDate) end
from
(
select
member.id as memberid,
(
select top 1 id
from membership
where memberid = member.id
and membership.StartDate <= getdate()
order by membership.enddate desc
) as membershipid
from member
) as LatestMembership
left join membership
on latestmembership.membershipid = membership.id
join member
on latestmembership.memberid = member.id
join AspNetusers
on member.AspNetUserId = AspNetUsers.Id
join Location
on member.HomeLocationId = Location.Id
left join Package
on membership.packageid = package.Id
left join PackageType
on package.packagetypeid = packagetype.Id
left join MembershipState
on membership.membershipstateid = membershipstate.Id
Order By aspNetusers.LastName desc
END
Below is what i have tried to do; however, it is duplicating the otherwise correct results based on the number of values in the WHERE IN join.
This on member.HomeLocationId = Location.Id
becomes on member.HomeLocationId IN (SELECT Value FROM fn_Split(#Locations, ','))
As seen below:
ALTER PROCEDURE [dbo].[GetMemberListing]
#Locations nvarchar(max)
AS
BEGIN
-- SET NOCOUNT ON added to prevent extra result sets from
-- interfering with SELECT statements.
SET NOCOUNT ON;
select
Member.Id,
AspNetUsers.Salutation,
AspNetUsers.FirstName,
AspNetUsers.PhotoUrl,
AspNetUsers.LastName,
AspNetUsers.Birthday,
AspNetUsers.Gender,
Member.IDType,
Member.JoinDate,
CONCAT (AspNetUsers.FirstName, ' ', AspNetUsers.LastName) as FullName,
AspNetUsers.CountryCode,
AspNetUsers.Email,
Location.Name as LocationName,
AspNetUsers.HomePhone as HomePhone,
coalesce(Package.Name,'No Package') as PackageName,
PackageTerm = case when Package.PackageIsReoccuring = 1 then 'Recurring' when Package.PackageIsSession = 1 then 'Paid In Full' when membership.TotalPrice = 0 then 'Free' when Package.PackagePayInFull = 1 then 'Paid In Full' end,
PackageType.Name as PackageType,
MembershipId = case when membership.id IS NULL THEN '' ELSE 0 end,
coalesce(membershipstate.name, 'N/A') as MembershipState,
MembershipStartDate = case when membership.StartDate IS NULL THEN '' ELSE CONVERT(varchar(50),membership.StartDate) end,
MembershipEndDate = case when membership.EndDate IS NULL THEN '' ELSE CONVERT(varchar(50),membership.EndDate) end
from
(
select member.id as memberid,
(
select top 1 id
from membership
where memberid = member.id
and membership.StartDate <= getdate()
order by membership.enddate desc
) as membershipid
from member
) as LatestMembership
left join membership
on latestmembership.membershipid = membership.id
join member
on latestmembership.memberid = member.id
join AspNetusers
on member.AspNetUserId = AspNetUsers.Id
join Location
on member.HomeLocationId IN (SELECT Value FROM fn_Split(#Locations, ','))
left join Package
on membership.packageid = package.Id
left join PackageType
on package.packagetypeid = packagetype.Id
left join MembershipState
on membership.membershipstateid = membershipstate.Id
Order By aspNetusers.LastName desc
END

Answer 1

Change to using your split function in the where clause. Don't use that function in the join.
In addition you don't really have a valid join condition on the locations table go back to this
on member.HomeLocationId = Location.Id
And later
Where member.HomeLocationId IN (SELECT Value FROM fn_Split(#Locations, ','))