Optional EmbeddedModel not working about odmantic HOT 3 OPEN

import traceback
from typing import List

from odmantic import Model, EmbeddedModel, Field, Reference


class Error(EmbeddedModel):
    code: int = Field(500)
    message: str = Field("Internal Server Error")


class Document(Model):
    text: str = Field(...)
    error: List[Error] = Reference(key_name="dsError")

try:
    print(Document(text="This is a test", error=[]).doc())
except Exception as e:
    print(traceback.format_exc())
try:
    print(Document(text="This is a failure", error=[Error(code=404, message="Not found")]).doc())
except Exception as e:
    print(traceback.format_exc())

{'text': 'This is a test', 'error': [], '_id': ObjectId('661e929c48b2346427e89de1')}
{'text': 'This is a failure', 'error': [{'code': 404, 'message': 'Not found'}], '_id': ObjectId('661e929c48b2346427e89de2')}

class miniSeriesDTO(EmbeddedModel):
    losses: int
    progress: str
    target: int
    wins: int


class LeagueEntry(Model):
    leagueId: str
    queueType: str
    tier: TierEnum
    rank: RankEnum
    leaguePoints: int
    wins: int
    losses: int
    hotStreak: bool
    veteran: bool
    freshBlood: bool
    inactive: bool
    miniSeries: Optional[miniSeriesDTO] = None