Error ambiguousmatchexception: the request matched multiple endpoints

See more:

C#

.NET

MVC5

ASP.NET-Core

Hello, when I am trying to access one of the views in my ASP .NET MVC app I am getting following error:
AmbiguousMatchException: The request matched multiple endpoints. Matches:

RockWorld.Web.Controllers.Admin.PageParametersController.Index (RockWorld.Web)
RockWorld.Web.Controllers.Admin.PageParametersController.OperationProgress (RockWorld.Web).

It is the only controller on my app on which I am getting this error.

My controller:

    [Authorize(Roles = UserGroups.CmsAdmins)]
	[Route("/Admin/[controller]")]
	public class PageParametersController : Controller
	{
        private readonly IPageParametersService _pageParametersService;
        private readonly IApplicationOptions _applicationOptions;
        private readonly ILogger<PageParametersController> _logger;
        private readonly IPageParametersProgressService _progressService;
        private readonly IRequiredClientResourceList _requiredClientResourceList;

        public PageParametersController(
            IPageParametersService pageParametersService,
            IApplicationOptions applicationOptions,
            ILogger<PageParametersController> logger,
            IPageParametersProgressService pageParametersProgressService,
            IRequiredClientResourceList requiredClientResourceList)
        {
            _pageParametersService = pageParametersService;
            _applicationOptions = applicationOptions;
            _logger = logger;
            _progressService = pageParametersProgressService;
            _requiredClientResourceList = requiredClientResourceList;
        }

        public ActionResult Index()
        {
            if (!_applicationOptions.IsUpdatePageParameters)
            {
                return null;
            }

            _requiredClientResourceList.RequireStyleInline($"{AdminLayoutCssClasses.MT6} {AdminLayoutCssClasses.InfoTextArea} {AdminLayoutCssClasses.EpiButtonDefault}").AtHeader();

            return View("/Views/Admin/PageParameters/Index.cshtml");
        }

        [HttpPost]
        public ActionResult Update(IFormFile file)
        {
            if (_progressService.IsRunning)
            {
                return OperationProgress();
            }

            if (!_applicationOptions.IsUpdatePageParameters)
            {
                return null;
            }

            if (file == null)
            {
                _progressService.AddErrorLog("File not found");

                return new JsonResult(new PageParametersResult { IsRunning = false });
            }

            string fileExtension = Path.GetExtension(file.FileName);

            if (fileExtension != ".csv")
            {
	            _progressService.AddErrorLog("Invalid file format");

	            return new JsonResult(new PageParametersResult { IsRunning = false });
            }

            List<PageParameters> pageParametersList = _pageParametersService.ConvertCsvContentToList(file);

            if (pageParametersList == null || !pageParametersList.Any())
            {
	            return new JsonResult(new PageParametersResult { IsRunning = false });
            }

            pageParametersList.RemoveAll(x => x == null);

            CheckDuplicates(pageParametersList);

            Task task = null;
            task = Task.Run(() =>
            {
	            try
	            {
		            _progressService.SetApplicationStatus(true, task);

		            _pageParametersService.UpdatePageParameters(pageParametersList);
	            }
	            catch (Exception ex)
	            {
		            _logger.LogError(ex.Message);
		            _progressService.AddInfoLog("Update parameters failed");
	            }
	            finally
	            {
		            _progressService.SetApplicationStatus(false, task);
	            }
            });

            return new JsonResult(new PageParametersResult { IsRunning = true });
        }

        public ActionResult OperationProgress()
        {
            string logs = _progressService.GetLogs();

            return new JsonResult(new PageParametersResult { IsRunning = _progressService.IsRunning, Logs = logs });
        }

        private void CheckDuplicates(List<PageParameters> pageParametersList)
        {
            var duplicatedIds = pageParametersList.GroupBy(x => x.EPIPageId).Where(x => x.Count() > 1).Select(x => x.Key)
                .ToList();

            if (duplicatedIds.Any())
            {
                foreach (var id in duplicatedIds)
                {
                    _progressService.AddErrorLog($"Duplicated value for page with id: {id}");

                    pageParametersList.RemoveAll(x => x.EPIPageId == id);
                }
            }
        }
    }
}

My view:

@using EPiServer.Framework.Web
@using EPiServer.Framework.Web.Mvc.Html
@using RockWorld.Web
@using EPiServer.Framework.Web.Resources
@{
Layout = "~/Views/Layouts/ToolsLayout.cshtml";
ViewBag.SectionTitle = "Page parameters";
}
<div class="mt-6 ms-2">
      <h2>@ViewBag.SectionTitle</h2>
      <div class="epi-contentContainer epi-padding">
         <div class="epi-contentArea">
            <h1 class="EP-prefix">
               Update page parameters
            </h1>
            <p class="EP-systemInfo">This tool will go through all pages and update ones which are specified in excel file.</p>
            <div id="FullRegion_ValidationSummary" class="EP-validationSummary" style="color: Black; display: none;"></div>
         </div>
         <div class="epi-contentArea epi-formArea">
            <fieldset class="border rounded-3 p-3">
               <legend class="float-none w-auto px-3">Choose csv file.</legend>
               <label>Excel File</label>
               <input id="parametersFile" type="file" name="file" accept=".csv" />
            </fieldset>
            <p class="mt-2">Only pages specified in file will be updated.</p>
            <div class="epi-buttonDefault">
               
               <input class="epi-cmsButton-text epi-cmsButton-tools epi-cmsButton-Refresh" type="submit" name="btnSubmit" id="updateParametrsSubmit" value="Submit" />
               
            </div>
         </div>
         <div>
            <h3>Result:</h3>
            <textarea id="InfoTextArea" disabled rows="10" cols="50"></textarea>
         </div>
      </div>
   </div>
   @Html.RequiredClientResources(RenderingTags.Header)
   @Url.RenderScripts(BundleNames.DependenciesBundle, BundleNames.PageParametersUpdate)

What I have tried:

I tried to rectify this issue by adding route constraints to the methods, but this didn't fix my issue.