POST requests - different requests return the same response

[Default_001]

Hi All,

I'm trying to retrieve data from a site by sending a POST request which appears to work, however, it returns the same result despite the request changing.

For example:
1. if I change the dates
2. submit the request
3. it will still return the same result as if I never changed the dates

I check this via the website manually incase it case the data was in fact the same and found the data was different so something is must be wrong with my request.

Any help would be greatly appreciated! I'm stuck with this.

Bdate = 20210220
Adate = 20220220   

#Prepare the column headers
BdateVal = str(Bdate) + " Est. value ($m)"
AdateVal = str(Adate) + " Est. value ($m)"

#retrive payload and enter index + dates
d =  {"__EVENTTARGET":"m$m$p1$p1$ITrakResults$DownloadButtoniTrak",
      "__EVENTARGUMENT":"",
      "__LASTFOCUS":"",
      "__VIEWSTATE":VS,
      "__VIEWSTATEGENERATOR":VSG ,
      "__SCROLLPOSITIONX":0,
      "__SCROLLPOSITIONY":0,
      "m$m$p1$p1$ITrakFilter$ddlInvestmentIn":352,
      "m$m$p1$p1$ITrakFilter$ddlComparisonPeriod":Bdate,
      "m$m$p1$p1$ITrakFilter$HiddenFieldLatterDate":Adate,
      "m$m$p1$p1$ITrakFilter$txtInvestorName":"",
      "m$m$p1$p1$ITrakFilter$ddlInvestmentStyle":"",
      "m$m$p1$p1$ITrakFilter$ddlInvestorList":"All Company Lists",
      "m$m$p1$p1$ITrakFilter$ddlInvestmentTrends":0,
      "m$m$p1$p1$ITrakFilter$slider_min":0,
      "m$m$p1$p1$ITrakFilter$slider_max":71000,
      "m$m$p1$p1$ITrakFilter$txtSliderLeftValue":0,
      "m$m$p1$p1$ITrakFilter$txtSliderRightValue":71000,
      "m$m$p1$p1$ITrakFilter$ucLocation$Location":"RadioButtonLocationIgnore",
      "m$m$p1$p1$ITrakFilter$ucLocation$DropDownRegions":0,
      "m$m$p1$p1$ITrakFilter$ucLocation$DropDownCountries":0}

params = {"InvIn":352,
          "FormerDateID":Bdate,
          "Holders":0,
          "ShowDetail":"True",
          "InvName":"",
          "sort":"LatterEstMarketSegmentValue",
          "sortAsc":"False"}
   
#Post request
GetCSV = s.post("https://secure.somewebsite.com/iTrak/Default.aspx?",params=params, headers=DownloadHeaders, data=d)

Snippet of Chrome Dev tool to view the payload with the request: https://ibb.co/yShrqdx