Need help calculating working hours difference between two dates

I am creating day difference betweek created and closed the tickets
My requirement is 
if ticket got created non working hours I should adjust the time to working hours
ex: if ticket create morning 7 it should adjust same day 8 am (my working hours are 8AM-5PM)
if any ticket created after 5PM should change to next day 8AM 
To calculate accurate result 
same if any ticket opend in weekends or holidays should refelct to next working day

Below is my Mcode which is not working for the above cases and result returning with error

let
// Load data
Source = Sql.Database("RV2IVWPBI1P\RAYAMSSQLSERVER", "RayaOperationsData"),
SR = Source{[Schema="dbo", Item="Fact_Siebel_ServiceRequest"]}[Data],

// Remove unwanted columns
RemovedCols = Table.RemoveColumns(SR, {
"SR_TYPE", "SUB_AREA", "PRIORITY", "REQUESTOR_NAME_EN", "SEVERITY",
"SR_DUE_DATE", "TOTAL_TIME", "VEHICLE_MAKE", "VEHICLE_MODEL", "MODEL_YEAR",
"PENDING_PAYMENT_START", "PENDING_PAYMENT_END", "LAST_UPD", "dw_created", "dw_last_upd"
}),

ChangedTypes = Table.TransformColumnTypes(RemovedCols, {
{"SR_CREATED", type datetime},
{"SR_CLOSE_DATE", type datetime}
}),

// Define working hours
WorkingStart = #time(8, 0, 0),
WorkingEnd = #time(17, 0, 0),

// 🟨 Holiday List
HolidayList = {
#date(2025, 3, 30), #date(2025, 3, 31), #date(2025, 4, 1), #date(2025, 4, 2),
#date(2025, 6, 5), #date(2025, 6, 8), #date(2025, 6, 9), #date(2025, 6, 10)
},

AdjustedStart = Table.AddColumn(ChangedTypes, "AdjustedStart", each
let
dt = [SR_CREATED],
defaultTime = #time(8, 0, 0),
workingEnd = #time(17, 0, 0),
safeDT = if dt = null then DateTime.LocalNow() else dt,
t = Time.From(safeDT),
d = Date.From(safeDT),
dow = Date.DayOfWeek(d, Day.Sunday),
isWeekend = dow = 5 or dow = 6, // Friday = 5, Saturday = 6 (Sunday = 0)
isHoliday = List.Contains(HolidayList, d),

nextWorkingDate =
List.First(
List.Select(
List.Dates(d + 1, 7, #duration(1,0,0,0)),
each
let wd = Date.DayOfWeek(_, Day.Sunday)
in (wd <> 5 and wd <> 6) and not List.Contains(HolidayList, _)
)
),

adjusted =
if isWeekend or isHoliday then
DateTime.From(nextWorkingDate & defaultTime)
else if t < defaultTime then
DateTime.From(d & defaultTime)
else if t >= workingEnd then
DateTime.From(nextWorkingDate & defaultTime)
else
safeDT

in
adjusted,
type datetime
),

// ✅ Adjust Closed Date
AdjustedEnd = Table.AddColumn(AdjustedStart, "AdjustedEnd", each
let
dt = if [SR_CLOSE_DATE] = null then DateTime.LocalNow() else [SR_CLOSE_DATE],
t = Time.From(dt),
d = Date.From(dt),
adjusted =
if t < WorkingStart then
DateTime.From(d + WorkingStart)
else if t > WorkingEnd then
DateTime.From(d + WorkingEnd)
else dt
in
adjusted
, type datetime),

// Date Range
AddDateRange = Table.AddColumn(AdjustedEnd, "DateRange", each
let
s = Date.From([AdjustedStart]),
e = Date.From([AdjustedEnd])
in
List.Dates(s, Duration.Days(e - s) + 1, #duration(1, 0, 0, 0))
, type list),

// Working Days (Sunday–Thursday, excluding holidays)
WorkingDates = Table.AddColumn(AddDateRange, "WorkingDates", each
List.Select([DateRange], each Date.DayOfWeek(_, Day.Sunday) <= 4 and not List.Contains(HolidayList, _))
, type list),

// Calculate Working Hours
WorkingHours = Table.AddColumn(WorkingDates, "WorkingHours", each
let
startDT = [AdjustedStart],
endDT = [AdjustedEnd],
startDate = Date.From(startDT),
endDate = Date.From(endDT),
dates = [WorkingDates],
hours = List.Sum(
List.Transform(dates, each
let
currentDate = _,
startTime = if currentDate = startDate then Time.From(startDT) else WorkingStart,
endTime = if currentDate = endDate then Time.From(endDT) else WorkingEnd,
validStart = if startTime < WorkingStart then WorkingStart else startTime,
validEnd = if endTime > WorkingEnd then WorkingEnd else endTime,
duration = Duration.TotalHours(validEnd - validStart)
in
if validEnd > validStart then duration else 0
)
)
in
if startDT = null or endDT = null then null else Number.Round(hours, 2)
, type number),

// Calculate SLA Working Days (9 hours per day rule)
SLA_WorkingDays = Table.AddColumn(WorkingHours, "SLA_WorkingDays", each
let
wh = [WorkingHours]
in
if wh = null then null
else if wh < 9 then 0
else Number.RoundUp(wh / 9)
, type number),

Cleanup = Table.RemoveColumns(SLA_WorkingDays, {"DateRange", "WorkingDates"})
in
Cleanup