Get User in Registered Role

I have custom User, Role and UserRole table, with User having an ICollection of UserRole

    public partial class UserRoleMap
    {
        public UserRoleMap(EntityTypeBuilder<UserRole> builder)
        {
            builder.ToTable("UserRole");
            builder.HasKey(ur => new { ur.UserId, ur.RoleId });

            builder.HasOne(ur => ur.User)
                .WithMany(u => u.UserRoles)
                .HasForeignKey(ur => ur.UserId);
        }
    }

Here is code snippet from UserExtensions.cs class

        public static bool IsInRole(this User user, string roleSystemName,
            bool onlyActiveRoles = true)
        {
            if (user == null)
                throw new ArgumentNullException(nameof(user));
            if (string.IsNullOrEmpty(roleSystemName))
                throw new ArgumentNullException(nameof(roleSystemName));
            return user.UserRoles.FirstOrDefault(ur => (!onlyActiveRoles
                || ur.Role.Active) && (ur.Role.SystemName == roleSystemName)) != null;
        }

        public static bool IsRegistered(this User user, bool onlyActiveRoles = true)
        {
            return IsInRole(user, SystemRoleNames.Registered, onlyActiveRoles);
        }

Now whenever I try to use this in project

if (!user.IsRegistered())
    ... something to happen ...

It doesn't seem to work. Any info would be greatly appreciated. Thank you!