Bring next value after condition - sql

Question

I am trying to fetch the next value after the condition is found. In this case, it is a row from 13/05/2021 the result I want to see is the row from 19/05/2021 Cte and CTE1 bring correct results.
I can't figure out what is wrong with my query.
<with cte as
(
select
customerid
,max(timestamp) as [Case Submitted]
,row_number() over (partition by [CustomerId] order by [CustomerId] ,max([timestamp]) desc) as rownum
from Table1
where substatus = 'Case Submitted'
and timestamp > '2021-01-01'
Group by
customerid
,timestamp
)
,CTE2 as
(
Select *
from cte
Where rownum = 1
),
CTE3 as
(
select
PS.customerid
,(PS.timestamp) as [Customer Support]
,row_number() over (partition by PS.customerid order by PS.customerid ) as rownum
from Table1 PS
left join CTE2 C2 on C2.customerid = PS.customerid and C2.[Case Submitted] > PS.timestamp and C2.rownum =1
where status = 'Customer Support'
and timestamp > '2021-01-01'
Group by
PS.customerid
,ps.timestamp
)
Select*
from CTE3>

Answer 1

untested notepad scribble
with CTE1 as
(
select
customerid
, [timestamp] as [Case Submitted]
, rownum = row_number() over (partition by CustomerId order by [timestamp] desc)
from Table1
where substatus = 'Case Submitted'
and [timestamp] > cast('2021-01-01' as date)
),
CTE2 AS
(
select
PS.customerid
, PS.timestamp as [Customer Support]
, rownum = row_number() over (partition by PS.customerid order by PS.timestamp)
from Table1 as PS
join CTE1 as C1
on C1.customerid = PS.customerid
and C1.[Case Submitted] > PS.[timestamp]
and C1.rownum = 1
where PS.status = 'Customer Support'
and [timestamp] > cast('2021-01-01' as date)
)
select *
from CTE2
where rownum = 1