RazorLight email template generator not working after update to .NET 8.0

Question

So it appears, that after updating my project to .NET 8.0, and updating all the NuGet packages to the latest available versions, email content generator I use stopped working. Exception that I get looks like this:

An unhandled exception has occurred while executing the request.
System.TypeLoadException: Type '<ExecuteAsync>d__0' from assembly 'hmc151k1.dzl, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null' tried to override method 'MoveNext' but does not implement or inherit that method.
   at RazorLight.CompiledTemplates.GeneratedTemplate.ExecuteAsync()
   at RazorLight.TemplateRenderer.RenderPageCoreAsync(ITemplatePage page, PageContext context)
   at RazorLight.TemplateRenderer.RenderPageAsync(ITemplatePage page, PageContext context, Boolean invokeViewStarts)
   at RazorLight.TemplateRenderer.RenderAsync(ITemplatePage page)
   at RazorLight.EngineHandler.RenderTemplateAsync[T](ITemplatePage templatePage, T model, TextWriter textWriter, ExpandoObject viewBag)
   at RazorLight.EngineHandler.RenderTemplateAsync[T](ITemplatePage templatePage, T model, ExpandoObject viewBag)
   at RazorLight.EngineHandler.CompileRenderAsync[T](String key, T model, ExpandoObject viewBag)
   at API.Service.Email.Helpers.RazorParser.ParseAsync[T](String template, T model) in D:\Projects\Projekti\API\api\API.Service\Email\Helpers\RazorParser.cs:line 28
   at API.Service.Email.Helpers.RazorParser.UsingTemplateFromEmbeddedAsync[T](String path, T model) in D:\Projects\Projekti\API\api\API.Service\Email\Helpers\RazorParser.cs:line 20
   at API.Service.Email.EmailContentGenerator.GenerateAsync[T](T emailDataModel) in D:\Projects\Projekti\API\api\API.Service\Email\EmailContentGenerator.cs:line 51
   at API.Service.Email.EmailDispatcher.Dispatch[T](String recipient, String subject, T emailDataModel) in D:\Projects\Projekti\API\api\API.Service\Email\EmailDispatcher.cs:line 22
   at API.Service.Auth.GenerateLoginTokenHandler.Handle(GenerateLoginTokenCommand request, CancellationToken cancellationToken) in D:\Projects\Projekti\API\api\API.Service\Auth\GenerateLoginTokenHandler.cs:line 73
   at API.Controllers.AuthController.GenerateLoginToken(LoginTokenGenerateViewModel loginViewModel) in D:\Projects\Projekti\API\api\API\Controllers\AuthController.cs:line 63
   at Microsoft.AspNetCore.Mvc.Infrastructure.ActionMethodExecutor.TaskOfIActionResultExecutor.Execute(ActionContext actionContext, IActionResultTypeMapper mapper, ObjectMethodExecutor executor, Object controller, Object[] arguments)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeActionMethodAsync>g__Awaited|12_0(ControllerActionInvoker invoker, ValueTask`1 actionResultValueTask)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeNextActionFilterAsync>g__Awaited|10_0(ControllerActionInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Rethrow(ActionExecutedContextSealed context)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeInnerFilterAsync>g__Awaited|13_0(ControllerActionInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeNextResourceFilter>g__Awaited|25_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Rethrow(ResourceExecutedContextSealed context)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeFilterPipelineAsync>g__Awaited|20_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeAsync>g__Logged|17_1(ResourceInvoker invoker)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeAsync>g__Logged|17_1(ResourceInvoker invoker)
   at Microsoft.AspNetCore.Routing.EndpointMiddleware.<Invoke>g__AwaitRequestTask|7_0(Endpoint endpoint, Task requestTask, ILogger logger)
   at Microsoft.AspNetCore.Authorization.AuthorizationMiddleware.Invoke(HttpContext context)
   at Microsoft.AspNetCore.Authentication.AuthenticationMiddleware.Invoke(HttpContext context)
   at Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddlewareImpl.Invoke(HttpContext context)

The part between from assembly and Version=0.0.0.0 changes every time this exception is raised.

RazorParser.cs is implemented like this:

    public class RazorParser
    {
        private readonly Assembly assembly;

        public RazorParser(Assembly assembly)
        {
            this.assembly = assembly;
        }

        public async Task<string> UsingTemplateFromEmbeddedAsync<T>(string path, T model)
        {
            var template = EmbeddedResourceHelper.GetResourceAsString(assembly, GenerateFileAssemblyPath(path, assembly));
            return await ParseAsync(template, model);
        }

        async Task<string> ParseAsync<T>(string template, T model)
        {
            var project = new InMemoryRazorLightProject();
            var engine = new RazorLightEngineBuilder().UseProject(project).Build();

            return await engine.CompileRenderStringAsync<T>(Guid.NewGuid().ToString(), template, model);
        }

        string GenerateFileAssemblyPath(string template, Assembly fileAssembly)
        {
            string assemblyName = fileAssembly.GetName().Name;
            return $"{assemblyName}.Email.{template}.{"cshtml"}";
        }
    }

Additionally, after updating the packages I have converted my project from having Program.cs and Startup.cs files to just having Program.cs file. But I have checked multiple times, and everything is moved from Startup.cs to Program.cs, nothing has been left behind. Maybe someone has had a similar issue, and had already solved it?