Key data annotation not working when assigned to a separate partial class in my razor web app using efcore .netcore - data-annotations

Question

I am developing an application in razor web apps (asp.netcore) and scaffolding db tables using efcore.
I performed a db-scaffold on my OnlineForms data table, which created my OnlineForms.cs Class. When i directly put the [key] attribute on top of the formid property in this class, I can save to the data table without any issues.
But when I move the [key] data annotation into the partial class OnlineFormsValidation, which references OnlineForms, through the [ModelMetadataType] attribute, and I try to save data; I get the error: "The entity type 'OnlineForm' requires a primary key to be defined."
The Required annotations work properly from inside OnlineFormsValidation class, but the [Key] annotation does not.
Thank you in advance. Any help would be greatly appreciated.
OnlineForm.cs:
namespace VehicleTakeHomeApp.Data.Models
{
public partial class OnlineForm {
[Key] <== works if i put it here, but I want to move it to OnlineFormValidation.cs
public int FormId { get; set; }
public string EmployeeId { get; set; }
public string Name { get; set; }
}
}
OnlineFormValidation.cs:
using Microsoft.AspNetCore.Mvc;
using System.ComponentModel.DataAnnotations;
namespace VehicleTakeHomeApp.Data.Models
{
[ModelMetadataType(typeof(OnlineFormValidation))]
public partial class OnlineForm
{
}
public class OnlineFormValidation
{
[Key] <== this annotation is not getting picked up, even though the Required annotations below it get picked up.
public int FormId { get; set; }
[Required(ErrorMessage = "Employee ID is required.")]
public string EmployeeId { get; set; }
[Required(ErrorMessage = "Name is required.")]
public string Name { get; set; }
}
}

Answer 1

I had the OnModelCreating method in my dbcontext class commented out. This method contains the HasKey() from the initial db-scaffold.
I uncommented the OnModelCreating method, and now I don't need to add the [Key] annotation, to either class and it works.
It's more of a workaround then a solution, but its works.