Custom Sorting Issue in Column Chart

I have written Case statement to reflect the same order but still the order is missing which you can see in column chart as per statement below:
CASE WHEN
(REMAP_TIMESTAMPS(ROUND_DAY(<%=Variable_4%>), DAYS) - REMAP_TIMESTAMPS(“VBAP”.“ERDAT”, DAYS)) < 0
THEN ‘<0:’
WHEN
(REMAP_TIMESTAMPS(ROUND_DAY(<%=Variable_4%>), DAYS) - REMAP_TIMESTAMPS(“VBAP”.“ERDAT”, DAYS)) = 0
THEN ‘Same Day’
WHEN
(REMAP_TIMESTAMPS(ROUND_DAY(<%=Variable_4%>), DAYS) - REMAP_TIMESTAMPS(“VBAP”.“ERDAT”, DAYS)) = 1
THEN ’ 1 ’
WHEN
(REMAP_TIMESTAMPS(ROUND_DAY(<%=Variable_4%>), DAYS) - REMAP_TIMESTAMPS(“VBAP”.“ERDAT”, DAYS)) = 2
THEN ’ 2 ’
WHEN
(REMAP_TIMESTAMPS(ROUND_DAY(<%=Variable_4%>), DAYS) - REMAP_TIMESTAMPS(“VBAP”.“ERDAT”, DAYS)) = 3
THEN ’ 3 ’
WHEN
(REMAP_TIMESTAMPS(ROUND_DAY(<%=Variable_4%>), DAYS) - REMAP_TIMESTAMPS(“VBAP”.“ERDAT”, DAYS)) = 4
THEN ’ 4 ’
WHEN
(REMAP_TIMESTAMPS(ROUND_DAY(<%=Variable_4%>), DAYS) - REMAP_TIMESTAMPS(“VBAP”.“ERDAT”, DAYS)) = 5
THEN ’ 5 ’
WHEN
(REMAP_TIMESTAMPS(ROUND_DAY(<%=Variable_4%>), DAYS) - REMAP_TIMESTAMPS(“VBAP”.“ERDAT”, DAYS)) > 5 AND
(REMAP_TIMESTAMPS(ROUND_DAY(<%=Variable_4%>), DAYS) - REMAP_TIMESTAMPS(“VBAP”.“ERDAT”, DAYS)) <= 10
THEN ‘6-10’
WHEN
(REMAP_TIMESTAMPS(ROUND_DAY(<%=Variable_4%>), DAYS) - REMAP_TIMESTAMPS(“VBAP”.“ERDAT”, DAYS)) > 10 AND
(REMAP_TIMESTAMPS(ROUND_DAY(<%=Variable_4%>), DAYS) - REMAP_TIMESTAMPS(“VBAP”.“ERDAT”, DAYS)) <= 15
THEN ‘11-15’
WHEN
(REMAP_TIMESTAMPS(ROUND_DAY(<%=Variable_4%>), DAYS) - REMAP_TIMESTAMPS(“VBAP”.“ERDAT”, DAYS)) > 15 AND
(REMAP_TIMESTAMPS(ROUND_DAY(<%=Variable_4%>), DAYS) - REMAP_TIMESTAMPS(“VBAP”.“ERDAT”, DAYS)) <= 20
THEN ‘16-20’
WHEN
(REMAP_TIMESTAMPS(ROUND_DAY(<%=Variable_4%>), DAYS) - REMAP_TIMESTAMPS(“VBAP”.“ERDAT”, DAYS)) > 20 AND
(REMAP_TIMESTAMPS(ROUND_DAY(<%=Variable_4%>), DAYS) - REMAP_TIMESTAMPS(“VBAP”.“ERDAT”, DAYS)) <= 25
THEN ‘21-25’
WHEN
(REMAP_TIMESTAMPS(ROUND_DAY(<%=Variable_4%>), DAYS) - REMAP_TIMESTAMPS(“VBAP”.“ERDAT”, DAYS)) > 25 AND
(REMAP_TIMESTAMPS(ROUND_DAY(<%=Variable_4%>), DAYS) - REMAP_TIMESTAMPS(“VBAP”.“ERDAT”, DAYS)) <= 30
THEN ‘26-30’
ELSE ‘>30’
END

Please find the output after giving the above code, I dont know why blank is showing 11 count and <0 has to start and end with > 30 but it is not happening

In addition, i need the below points to be addressed:

  1. – are showing in the graph eventhough i have not stated in case when statement
  2. Can i get fixed x axis instead of dynamic