I want to port a very old pdf processing application to .Net and in the process convert handelbars templates to Razor.

I am scratching my head on why a TagHelper is not being picked up.

namespace NemoPdfNet.TagHelpers
{
    public class LogoTagHelper : TagHelper
    {
        public required string Brand { get; set; }

        public required Dictionary<string, string> Logos { get; set; }

        public override void Process(TagHelperContext context, TagHelperOutput output)
        {
            if (!string.IsNullOrEmpty(Brand) && Brand == "whitelabel")
                output.SuppressOutput();
            else
            {
                output.TagName = "img";

                if (!Logos.ContainsKey(Brand))
                {
                    output.Attributes.SetAttribute("src", Logos["default"]);
                    output.Attributes.SetAttribute("class", "pdf-header-logo default");
                }
                else
                {
                    output.Attributes.SetAttribute("src", Logos[Brand]);
                    output.Attributes.SetAttribute("class", "pdf-header-logo " + Brand);
                }
            }
        }
    }
}

ViewImports.cshtml

@using NemoPdfNet
@using NemoPdfNet.Models
@using NemoPdfNet.Requests
@addTagHelper *, Microsoft.AspNetCore.Mvc.TagHelpers
@addTagHelper *, NemoPdfNet.TagHelpers

If I now want to use this, it does not get resolved:

@if (!string.IsNullOrEmpty(Model.Brand))
{
    <partial name="_LogoPartial"
        model="new NemoPdfNet.Models.LogoViewModel { Brand = Model.Brand, Logos = Model.Logos }" />
    <logo brand="Model.Brand" logos="Model.Logos"></logo>
}

While the partial is working as expected and delivers the functionality, the logo taghelper gets rendered as

<logo brand="default" logos="System.Collections.Generic.Dictionary`2[System.String,System.String]"></logo>

What am I doing wrong?