Migration error: multiple default values specified for column “Id” of table “ProductsToCompare”

I added field 'Id' to the model. Before this I used composite key, but with it I couldn't add item with existing Id. And now by some reason I can't update database after adding migration.

public class ProductToCompare
{
    public int Id { get; set; }
    public int ProductComparsionId { get; set; }
    public ProductComparsion ProductComparsion { get; set; }
    public int ProductId { get; set; }
    public Product Product { get; set; }        
}

modelBuilder.Entity<ProductToCompare>(typeBuilder =>
{
    typeBuilder.ToTable(nameof(AppDbContext.ProductsToCompare));
    //!typeBuilder.HasKey(z => new { z.ProductId, z.ProductComparsionId });
    typeBuilder.HasKey(z => z.Id);
    typeBuilder.HasOne(z => z.ProductComparsion).WithMany(z => z.ProductsToCompare).HasForeignKey(z => z.ProductComparsionId);
    typeBuilder.HasOne(z => z.Product).WithMany().HasForeignKey(z => z.ProductId).OnDelete(DeleteBehavior.SetNull);
});

cmd

26.03.2020 10:00:22 ERROR
Microsoft.EntityFrameworkCore.Database.Command:
Failed executing DbCommand (64ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
ALTER TABLE "ProductsToCompare" ADD "Id" serial NOT NULL DEFAULT 0;
Npgsql.PostgresException (0x80004005): 42601: multiple default values specified for column "Id" of table "ProductsToCompare"
   at Npgsql.NpgsqlConnector.<>c__DisplayClass161_0.<<ReadMessage>g__ReadMessageLong|0>d.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at Npgsql.NpgsqlConnector.<>c__DisplayClass161_0.<<ReadMessage>g__ReadMessageLong|0>d.MoveNext() in C:\projects\npgsql\src\Npgsql\NpgsqlConnector.cs:line 1032
--- End of stack trace from previous location where exception was thrown ---
   at Npgsql.NpgsqlDataReader.NextResult(Boolean async, Boolean isConsuming) in C:\projects\npgsql\src\Npgsql\NpgsqlDataReader.cs:line 467
   at Npgsql.NpgsqlDataReader.NextResult() in C:\projects\npgsql\src\Npgsql\NpgsqlDataReader.cs:line 332
   at Npgsql.NpgsqlCommand.ExecuteDbDataReader(CommandBehavior behavior, Boolean async, CancellationToken cancellationToken) in C:\projects\npgsql\src\Npgsql\NpgsqlCommand.cs:line 1219
   at Npgsql.NpgsqlCommand.ExecuteNonQuery(Boolean async, CancellationToken cancellationToken) in C:\projects\npgsql\src\Npgsql\NpgsqlCommand.cs:line 1042
   at Npgsql.NpgsqlCommand.ExecuteNonQuery() in C:\projects\npgsql\src\Npgsql\NpgsqlCommand.cs:line 1025
   at Microsoft.EntityFrameworkCore.Storage.Internal.RelationalCommand.Execute(IRelationalConnection connection, DbCommandMethod executeMethod, IReadOnlyDictionary`2 parameterValues)

Failed executing DbCommand (64ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
ALTER TABLE "ProductsToCompare" ADD "Id" serial NOT NULL DEFAULT 0;
Npgsql.PostgresException (0x80004005): 42601: multiple default values specified for column "Id" of table "ProductsToCompare"
   at Npgsql.NpgsqlConnector.<>c__DisplayClass161_0.<<ReadMessage>g__ReadMessageLong|0>d.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at Npgsql.NpgsqlConnector.<>c__DisplayClass161_0.<<ReadMessage>g__ReadMessageLong|0>d.MoveNext() in C:\projects\npgsql\src\Npgsql\NpgsqlConnector.cs:line 1032
--- End of stack trace from previous location where exception was thrown ---
   at Npgsql.NpgsqlDataReader.NextResult(Boolean async, Boolean isConsuming) in C:\projects\npgsql\src\Npgsql\NpgsqlDataReader.cs:line 467
   at Npgsql.NpgsqlDataReader.NextResult() in C:\projects\npgsql\src\Npgsql\NpgsqlDataReader.cs:line 332
   at Npgsql.NpgsqlCommand.ExecuteDbDataReader(CommandBehavior behavior, Boolean async, CancellationToken cancellationToken) in C:\projects\npgsql\src\Npgsql\NpgsqlCommand.cs:line 1219
   at Npgsql.NpgsqlCommand.ExecuteNonQuery(Boolean async, CancellationToken cancellationToken) in C:\projects\npgsql\src\Npgsql\NpgsqlCommand.cs:line 1042
   at Npgsql.NpgsqlCommand.ExecuteNonQuery() in C:\projects\npgsql\src\Npgsql\NpgsqlCommand.cs:line 1025
   at Microsoft.EntityFrameworkCore.Storage.Internal.RelationalCommand.Execute(IRelationalConnection connection, DbCommandMethod executeMethod, IReadOnlyDictionary`2 parameterValues)
   at Microsoft.EntityFrameworkCore.Storage.Internal.RelationalCommand.ExecuteNonQuery(IRelationalConnection connection, IReadOnlyDictionary`2 parameterValues)
   at Microsoft.EntityFrameworkCore.Migrations.MigrationCommand.ExecuteNonQuery(IRelationalConnection connection, IReadOnlyDictionary`2 parameterValues)
   at Microsoft.EntityFrameworkCore.Migrations.Internal.MigrationCommandExecutor.ExecuteNonQuery(IEnumerable`1 migrationCommands, IRelationalConnection connection)
   at Microsoft.EntityFrameworkCore.Migrations.Internal.Migrator.Migrate(String targetMigration)
   at Microsoft.EntityFrameworkCore.Design.Internal.MigrationsOperations.UpdateDatabase(String targetMigration, String contextType)
   at Microsoft.EntityFrameworkCore.Design.OperationExecutor.UpdateDatabase.<>c__DisplayClass0_1.<.ctor>b__0()
   at Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase.Execute(Action action)
42601: multiple default values specified for column "Id" of table "ProductsToCompare"