asp.net core filtering not working properly

Question

My filter is not working as intended. I have a OnGet

 

public async Task<IActionResult> OnGetAsync()
{
   var userId = User.FindFirstValue(ClaimTypes.NameIdentifier);
   var orgid = await _context.UsersData.Where(s => s.Id == userId).Select(s => s.OrgID).FirstOrDefaultAsync();
   var todayYear = DateTime.Today.Year;

 PTWContentsL = await _context.PTWContents.Where(s => s.OrgID == orgid && s.StartDate.Year == todayYear).ToListAsync();

return Page();
}

 which is listing all data but when I use a filter parameter is not working, I have empty results even if it should have at least all of the above. The parameter is sent because I checked on View

 

public async Task<IActionResult> OnPostFilteringIRAsync(string FilterIR)
        {
            Test = FilterIR;
            var userId = User.FindFirstValue(ClaimTypes.NameIdentifier);
            var orgid = await _context.UsersData.Where(s => s.Id == userId).Select(s => s.OrgID).FirstOrDefaultAsync();
            var todayYear = DateTime.Today.Year;

            PTWContentsL = await _context.PTWContents.Where(s => s.OrgID == orgid && s.StartDate.Year == todayYear && s.Issuer == FilterIR).ToListAsync();

            return Page();
        }

 the View and form

 

<form method="post">
    <div class="col-md-5 border border-primary pl-1">
        <div class="row no-gutters">
            <div class="col-md-12 text-center">
                <label class="form-control text-white" style="background-color:dodgerblue">Filter by Issuer/ Receiver</label>
            </div>
        </div>
        <div class="row no-gutters mb-1">
            <div class="col-md-10 mb-2">
                <select id="IRSelect" class="form-control ml-1">
                    <option value="">--Select Filtering Condition--</option>
                    <option value="1">Issuer</option>
                    <option value="2">Receiver</option>
                </select>
            </div>
            <div class="col-md-10">
                <select id="IRDetail" class="form-control ml-1" asp-items="@(new SelectList(string.Empty, "Issuer", "Issuer"))" onchange="assignData()">
                    <option value="">--Select Name--</option>
                </select>
                <input hidden id="IRName" asp-for="FilterIR" />
            </div>
            <div class="col-md-2 pl-1 text-center">
                <input class="btn btn-link ml-2" asp-page-handler="FilteringIR" style="border-color:dodgerblue; color:dodgerblue; width:100px; font-size:14px" type="submit" value="Apply Filter" />
            </div>
        </div>
    </div>
</form>