Using asp-page TagHelper for form element action renders "" instead of correct URL - razor-pages

Question

I have a razor page that that shows details of a search result (that is, clicking a search result link on the search page posts to the detail page). The detail page model has four properties that are written to from the post, which are used to post back to the search page:
[BindProperty]
public string PhysicianInput { get; set; }
[BindProperty]
public string LastNameInput { get; set; }
[BindProperty]
public string FirstNameInput { get; set; }
[BindProperty]
public int SelectedPhysician { get; set; }
In order to eliminate any other issues, I have removed all other code from the model except for the empty OnGet method that was there when the file was auto-generated.
The page file looks like this:
#page
#model Registrar.Pages.Followup.Physician.DetailModel
#{
ViewData["Title"] = "Physician Detail";
}
<h1 class="page-title">Physician Detail</h1>
<div class="center" style="width:700px;">
<form method="post" asp-page="/Followup/Physician/" id="PhysicianSearch">
<div style="text-align:right;">« Back to search results</div>
<input type="hidden" name="PhysicianNumber" id="PhysicianNumber" value="#Model.PhysicianInput" />
<input type="hidden" name="LastName" value="#Model.LastNameInput" />
<input type="hidden" name="FirstName" id="FirstName" value="#Model.FirstNameInput" />
</form>
<p>
Physician Number: #Model.PhysicianInput<br />
Last Name: #Model.LastNameInput<br />
First Name: #Model.FirstNameInput<br />
Selected Physician Number: #Model.SelectedPhysician
</p>
</div>
#section Scripts{
<script src="/js/physician.js"></script>
}
The js file there as one simple function that just submits the form:
function postBackToSearch() {
document.getElementById('PhysicianSearch').submit();
}
So when I debug the project, the page loads and the form tag looks like this:
<form method="post" id="PhysicianSearch" action="">
The action element is left blank. I have searched high and low and have found no pointers anywhere as to why the tagHelper would leave the action blank. And to top it off, the search page itself uses the same pattern and has no problem, the asp-page tagHelper works as expected.
This is my first website using asp.net core 5.0, and while much of it has been a breeze, every once in awhile I run into this kind of problem, and since the framework gives no feedback whatsoever on what the trouble might be it is next to impossible to debug. Does anyone have any idea what is going on here?
Any help would be much appreciated.

Answer 1

Well, to answer my own question, I found a workaround. And it's pretty unsatisfying, really.
The reason I'm relying on the asp-page tagHelper to fill in my form action is because their antiforgery functionality didn't like it when I added the form action directly to the page (and for reasons I don't understand due to my inexperience with the framework). So my solution is to allow the form action to be directly added to the page, which means disabling the antiforgery functionality in the post-receiving page model. At least that's easily done, all I did was add this attribute on top of the class:
[IgnoreAntiforgeryToken(Order = 1001)]
So this is my solution. The search page now accepts the post, but disabling the otherwise useful antiforgery functionality is pretty unsatisfying (like I said above). However, if someone happens upon this and has a better solution, please share!