Entity Framework: NOT NULL constraint when adding a second item

I'm following the Entity Framework documentation to add a list of string in my Sqlite database.

It works fine when i'm adding the first item.

But as soon as i try to add another item and SaveChanges() i get a exception:

SQLite Error 19: 'NOT NULL constraint failed: MyModels.Tags'

Here is the code, it mostly comes from the EF documentation page

namespace ArrayDatabaseTest.Models
{

    public class MyDatabase : DbContext
    {
        private string DbPath { get; }

        public MyDatabase()
        {
            string path = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Desktop), "Avalonia", "ArrayDatabaseTest");
            DbPath = Path.Join(path, "MyDatabase.db");
            Trace.WriteLine($"DbPath: {DbPath}");
        }

        protected override void OnConfiguring(DbContextOptionsBuilder options)
        {
            options.UseSqlite($"Data Source={DbPath}");
        }

        protected override void OnModelCreating( ModelBuilder modelBuilder )
        {
            modelBuilder.Entity<MyModel>()
                .Property(e => e.Tags)
                .HasConversion(
                    v => JsonSerializer.Serialize(v, (JsonSerializerOptions)null),
                    v => JsonSerializer.Deserialize<List<string>>(v, (JsonSerializerOptions)null),
                    new ValueComparer<ICollection<string>>(
                        (c1, c2) => c1.SequenceEqual(c2),
                        c => c.Aggregate(0, (a, v) => HashCode.Combine(a, v.GetHashCode())),
                        c => (ICollection<string>)c.ToList()));
        }

        public DbSet<MyModel> MyModels { get; set; }
    }

    public class MyModel
    {
        public long Id { get; set; }
        public string Name { get; set; } = "";

        public ICollection<string> Tags { get; set; }
    }
}

// In my ViewModel the code to add a new item
public void AddToMyDatabase( string name )
{
    MyDatabase.MyModels.Add(new MyModel
    {
        Name = name,
        Tags = new List<string>()
    });
    MyDatabase.SaveChanges();
}

How can i fix this issue ?

Thanks in advance for your answer.