ABP Validation from User Entity Extension

Question

ABP v4.4.4
I've added a few fields to User entity to MyProjectIdentityEfCoreEntityExtensionMappings.cs:

ObjectExtensionManager.Instance
    .MapEfCoreProperty<IdentityUser, Gender?>(UserExtensionNames.Gender)
    .MapEfCoreProperty<IdentityUser, UserStatus>(UserExtensionNames.UserStatus);

Before even attempting to add extension to IdentityUserCreateDto, I tried calling the create user endpoint /api/identity/users, and I'm hit with validation errors as below. 2 things I've taken note here:

1. Validation error for the nullable field is prompted
2. The non-nullable field validation error appeared twice.

2022-01-28 16:39:09.089 +08:00 [WRN] ModelState is not valid! See ValidationErrors for details. Volo.Abp.Validation.AbpValidationException: ModelState is not valid! See ValidationErrors for details. at Volo.Abp.AspNetCore.Mvc.Validation.ModelStateValidator.Validate(ModelStateDictionary modelState) at Volo.Abp.AspNetCore.Mvc.Validation.AbpValidationActionFilter.OnActionExecutionAsync(ActionExecutingContext context, ActionExecutionDelegate next) at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.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() --- End of stack trace from previous location --- at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.g__Awaited|25_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
2022-01-28 16:39:09.090 +08:00 [WRN] There are 3 validation errors:
The Gender field is required. (Gender)
The UserStatus field is required. (UserStatus)
The UserStatus field is required. (UserStatus)

2022-01-28 16:39:09.094 +08:00 [INF] Executing ObjectResult, writing value of type 'Volo.Abp.Http.RemoteServiceErrorResponse'. 2022-01-28 16:39:09.102 +08:00 [INF] Executed action Volo.Abp.Identity.IdentityUserController.CreateAsync (Volo.Abp.Identity.HttpApi) in 309.3593ms 2022-01-28 16:39:09.102 +08:00 [INF] Executed endpoint 'Volo.Abp.Identity.IdentityUserController.CreateAsync (Volo.Abp.Identity.HttpApi)'

My expected result is there should be 1 validation error for UserStatus field.
Anyone can share some light on what is going on?
Thanks in advance.