Can someone help me understand why page remote validation is preventing asp-handlers from firing?

Question

I'm facing an odd issue here.

I have a page where i have setup a PageRemote attribute to validate a field, and on the same page, i have 2 buttons that each call a distinct handler using the asp-page-handler property (1 to update the content, the other to delete it).

If i remove the PageRemote validation, the handlers for both buttons are triggered as expected, but when i leave the PageRemote validation on the page, the buttons specific handlers are not called, although the PageRemote handler is correctly triggered.

Furthermore, when leaving the PageRemote validation on the page, if i force its validation to return false, then afterwards the buttons trigger their respective handler, but if i do not force it, then the behaviour is as described earlier, where the handlers are not triggered.

Can someone explain me if there is a catch on using these two things on the same page, and/or how to overcome this?

Below is a sample of the page code:

public class EditModel : PageModel
{
    
    private IConfiguration _configuration;

    [Required(ErrorMessageResourceType = typeof(ErrorMessages),
        ErrorMessageResourceName = nameof(ErrorMessages.SlugRequired))]
    [MinLength(3, ErrorMessageResourceType = typeof(ErrorMessages),
        ErrorMessageResourceName = nameof(ErrorMessages.SlugMinLength))]
    [MaxLength(128, ErrorMessageResourceType = typeof(ErrorMessages),
        ErrorMessageResourceName = nameof(ErrorMessages.SlugMaxLength))]
    [RegularExpression(@"^[0-9a-zA-Z_/-]*$", ErrorMessageResourceType = typeof(ErrorMessages),
        ErrorMessageResourceName = nameof(ErrorMessages.SlugAllowedCharacters))]
    [PageRemote(ErrorMessageResourceType = typeof(ErrorMessages),
        ErrorMessageResourceName = nameof(ErrorMessages.SlugDuplicate),
        AdditionalFields = "__RequestVerificationToken,GenericContentDTO.GenericContent.GenericContentId",
        HttpMethod = "post",
        PageHandler = "CheckSlug")]
    [Display(Name = "URL Title")]
    [BindProperty]
    public string Slug { get; set; }

    [TempData]
    public string FormResultMessage { get; set; }

    [BindProperty]
    public GenericContentDTO GenericContentDTO { get; set; }

    public EditModel(IConfiguration configuration)
    {
        _configuration = configuration;
    }

    public IActionResult OnGet(Guid genericContentId)
    {
        if (genericContentId.ToString() == "")
        {
            return NotFound();
        }

        ...
        Code to load content
        ...

        return Page();

    }

    public async Task<IActionResult> OnPostUpdate()
    {

        if (!ModelState.IsValid)
        {
            return Page();
        }

        ...
        Code to update content
        ...

        return RedirectToPage(new { GenericContentId = GenericContentDTO.GenericContent.GenericContentId });

    }

    public IActionResult OnPostDelete()
    {

        ...
        Code to delete content
        

    }

    public JsonResult OnPostCheckSlug()
    {

        var token = HttpContext.Session.GetString("APIAuthorizationToken");

        CheckSlugDTO CheckSlug = new CheckSlugDTO
        {
            Slug = Slug,
            ContentId = GenericContentDTO.GenericContent.GenericContentId,
            Exists = true
        };

        CheckSlug = APICommunicationHelper.PostData<CheckSlugDTO>(CheckSlug, _configuration["AppConfigs:APIAddress"] + "api/CheckGenericContentSlugExistance", token);

        return new JsonResult(!CheckSlug.Exists);
    }
}

And of the Razor Code:

@page "{GenericContentId:Guid}"
@model MyProject.Pages.Generic_Contents.EditModel
@{
}

<form method="post" id="editForm" name="editForm" enctype="multipart/form-data">

<h3>@TempData["FormResultMessage"]</h3>

<ul class="nav nav-tabs">
    <li class="nav-item"><a class="nav-link active" data-toggle="tab" href="#main">Main</a></li>
    <li class="nav-item"><a class="nav-link" data-toggle="tab" href="#meta">Meta</a></li>
</ul>

<div class="tab-content">

    <div id="main" class="tab-pane active">
        <br />

        <div asp-validation-summary="ModelOnly" class="text-danger"></div>

        @Html.HiddenFor(model => model.GenericContentDTO.GenericContent.GenericContentId)

        <div class="form-group">
            <label asp-for="GenericContentDTO.GenericContent.Title" class="control-label"></label>
            <input asp-for="GenericContentDTO.GenericContent.Title" class="form-control" />
            <span asp-validation-for="GenericContentDTO.GenericContent.Title" class="text-danger"></span>
        </div>

        <div class="form-group">
            <label asp-for="Slug" class="control-label"></label>
            <input asp-for="Slug" class="form-control" />
            <span asp-validation-for="Slug" class="text-danger"></span>
        </div>

        <div class="form-group row">

            <div class="col-4">
                <label asp-for="GenericContentDTO.MainImage" class="control-label"></label>
                <input asp-for="GenericContentDTO.MainImage" type="file" class="form-control" />
            </div>

        </div>

        <div class="form-group">
            <label asp-for="GenericContentDTO.GenericContent.Summary" class="control-label"></label>
            @Html.TextAreaFor(model => model.GenericContentDTO.GenericContent.Summary, new { @class = "form-control", @rows = 5 })
            <span asp-validation-for="GenericContentDTO.GenericContent.Summary" class="text-danger"></span>
        </div>

        <div class="form-group">
            <label asp-for="GenericContentDTO.GenericContent.ContentText" class="control-label"></label>
            @Html.TextAreaFor(model => model.GenericContentDTO.GenericContent.ContentText, new { @class = "form-control editorHtml" })
        </div>

        <div class="form-group">
            <label asp-for="GenericContentDTO.GenericContent.IsActive" class="control-label"></label>
            @Html.CheckBoxFor(model => model.GenericContentDTO.GenericContent.IsActive)
        </div>

    </div>

    <div id="meta" class="tab-pane fade">
        <div class="form-group">
            <label asp-for="GenericContentDTO.GenericContent.MetaDescription" class="control-label"></label>
            @Html.TextAreaFor(model => model.GenericContentDTO.GenericContent.MetaDescription, new { @class = "form-control", @rows = 5 })
            <span asp-validation-for="GenericContentDTO.GenericContent.MetaDescription" class="text-danger"></span>
        </div>

        <div class="form-group">
            <label asp-for="GenericContentDTO.GenericContent.MetaKeywords" class="control-label"></label>
            @Html.TextAreaFor(model => model.GenericContentDTO.GenericContent.MetaKeywords, new { @class = "form-control", @rows = 5 })
            <span asp-validation-for="GenericContentDTO.GenericContent.MetaKeywords" class="text-danger"></span>
        </div>
    </div>


    <div class="form-group text-right">
        <a asp-area="" asp-page="/Generic-Contents" class="btn btn-secondary">Cancel</a>
        <button type="submit" class="btn btn-danger" asp-page-handler="Delete">Delete Content</button>
        <button type="submit" class="btn btn-primary" asp-page-handler="Update">Update Content</button>
    </div>

</div>

</form>

@section Scripts {
@{await Html.RenderPartialAsync("_ValidationScriptsPartial");}    
}

Thanks