net mvc: posting calculated date not working - asp.net-mvc

Question

I have an app where users get three suggestions for their order as datetime:
Don´t worry about the year, just an example.
If none of the suggestions fit users can generate three other suggestions in the future, based on the latest calculated date.
This works only once.
My View:
#using (Ajax.BeginForm("GenerateSuggestionDates", "Home", new { Area = "Planning" }, new AjaxOptions { HttpMethod = "POST", UpdateTargetId = "planeditbody" }, new { autocomplete = "off", id = "suggestiondatesform" }))
{
#Html.HiddenFor(model => model.LatestDate)
#Html.HiddenFor(model => model.AssemblyOrderID)
<i class="fa fa-refresh mt-2 mr-3" style="float: right; color: grey; cursor: pointer;" onclick="$('#suggestiondatesform').submit();"></i>
}
Model.LatestDate is always set to the latest date in controller, but that latest date works only once.
My Controller:
[HttpPost]
public ActionResult GenerateSuggestionDates(PlanEditSingleViewModel model)
{
var viewModel = new PlanEditSingleViewModel();
Dictionary<int, DateTime> suggestions = new Dictionary<int, DateTime>();
try
{
var date = model.LatestDate.AddDays(1);
var counter = 0;
while (counter >= 0 && counter < 3)
{
if (date.DayOfWeek != DayOfWeek.Saturday && date.DayOfWeek != DayOfWeek.Sunday)
{
suggestions.Add(counter, planningService.CheckDesiredDate(date, true, model.AssemblyOrderID, null, true)[0]);
date = date.AddDays(1);
counter++;
}
else
{
date = date.AddDays(1);
}
}
viewModel.Suggestions = suggestions;
viewModel.LatestDate = date.AddDays(-1);
viewModel.AssemblyOrderID = model.AssemblyOrderID;
return PartialView("~/Views/Shared/Modals/PlanEditBodySingle.cshtml", viewModel);
}
catch (Exception e)
{
return PartialView("~/Views/Shared/Modals/PlanEditBodySingle.cshtml", null);
}
}
I can´t find what´s wrong here. Any hints, tipps, suggestions?
Thanks in advance!

Answer 1

Something seemed to be wrong with the binding (?).
I changed the code to this:
#using (Ajax.BeginForm("GenerateSuggestionDates", "Home", new { Area = "Planning", LatestDate = Model.LatestDate.ToString(), AssemblyOrderID = Model.AssemblyOrderID }, new AjaxOptions { HttpMethod = "POST", UpdateTargetId = "planeditbody" }, new { autocomplete = "off", id = "suggestiondatesform" }))
{
<i class="fa fa-refresh mt-2 mr-3" style="float: right; color: grey; cursor: pointer;" onclick="$('#suggestiondatesform').submit();"></i>
}
Accordingly I edited the controller code. This works.