実行可能な処理が残っているのにも関わらず処理が終了する

前提・実現したいこと

Musicクラスのplay()、もしくはloop()を実行した際にYTDLSource.from_url()以降を処理したい。

発生している問題・エラーメッセージ

Musicクラスのplay()、もしくはloop()を実行するとYTDLSource.from_url()を実行する行で処理が終了し、次以降を処理してくれない。

該当のソースコード

Python
import asyncio

import discord
from discord.ext import commands
import traceback
import youtube_dl
import os
import urllib.request
import re


# Suppress noise about console usage from errors
youtube_dl.utils.bug_reports_message = lambda: ''

prefix = os.getenv('DISCORD_BOT_PREFIX', default='>')
lang = os.getenv('DISCORD_BOT_LANG', default='ja')
token = 'token'


ytdl_format_options = {
    'format': 'bestaudio/best',
    'outtmpl': '%(extractor)s-%(id)s-%(title)s.mp3',
    'restrictfilenames': True,
    'noplaylist': True,
    'nocheckcertificate': True,
    'ignoreerrors': False,
    'logtostderr': False,
    'quiet': True,
    'no_warnings': True,
    'postprocessors': [{
        'key': 'FFmpegExtractAudio',
        'preferredcodec': 'mp3',
        'preferredquality': '192',
    }],
    'source_address': '0.0.0.0'  # bind to ipv4 since ipv6 addresses cause issues sometimes: True
}

ffmpeg_options = {
    'options': '-vn'
}

ytdl = youtube_dl.YoutubeDL(ytdl_format_options)


class YTDLSource(discord.PCMVolumeTransformer):
    def __init__(self, source, *, data, volume=0.2):
        super().__init__(source, volume)

        self.data = data

        self.title = data.get('title')
        self.url = data.get('url')

    @classmethod
    async def from_url(cls, url, *, loop=None):
        loop = loop or asyncio.get_event_loop()
        data = await loop.run_in_executor(None, lambda: ytdl.extract_info(url, download=False))

        if 'entries' in data:
            # take first item from a playlist
            data = data['entries'][0]

        filename = data['url']
        ytdl.prepare_filename(data)
        return cls(discord.FFmpegPCMAudio(filename, **ffmpeg_options), data=data)


class AudioQueue(asyncio.Queue):
    def __init__(self):
        super().__init__(100)

    def __getitem__(self, idx):
        return self._queue[idx]

    def to_list(self):
        return list(self._queue)

    def remove(self, idx):
        del self._queue[idx]

    def reset(self):
        self._queue.clear()


class AudioStatus:
    def __init__(self, ctx: commands.Context, vc: discord.VoiceClient):
        self.vc: discord.VoiceClient = vc
        self.ctx: commands.Context = ctx
        self.queue = AudioQueue()
        self.playing = asyncio.Event()
        self.loopMode = False
        asyncio.create_task(self.playing_task())

    async def add_audio(self, title, path):
        await self.queue.put([title, path])

    def get_list(self):
        return self.queue.to_list()

    def remove(self, idx):
        self.queue.remove(idx)

    def reset(self):
        self.queue.reset()

    async def playing_task(self):
        while True:
            self.playing.clear()
            if self.loopMode:
                title, player = self.queue[0]
            else:
                title, player = await self.queue.get()
            self.vc.play(player, after=self.play_next)
            if not self.loopMode:
                await self.ctx.send(f'{title}を再生します。')
            await self.playing.wait()

    def play_next(self, err=None):
        self.playing.set()

    async def leave(self):
        self.queue.reset()
        if self.vc:
            await self.vc.disconnect()
            self.vc = None

    @property
    def is_playing(self):
        return self.vc.is_playing()

    def resume(self):
        self.vc.stop()

    def pause(self):
        self.vc.stop()

    def stop(self):
        self.vc.stop()


class Music(commands.Cog):
    def __init__(self, bot):
        self.bot = bot
        self.audio_statuses = ""

    # command to connect to voice channel
    @commands.command(aliases=["s"])
    async def start(self, ctx):
        """Joins a voice channel"""

        if ctx.author.voice is None:
            await ctx.send('先にボイスチャンネルに接続してください…。')
        else:
            if ctx.guild.voice_client:
                if ctx.author.voice.channel == ctx.guild.voice_client.channel:
                    await ctx.send('既に接続済みです…。')
                else:
                    await ctx.voice_client.disconnect()
                    await asyncio.sleep(0.5)
                    vc = await ctx.author.voice.channel.connect()
                    self.audio_statuses = AudioStatus(ctx, vc)
                    await ctx.send('ボイスチャンネルを変更しました。')
            else:
                vc = await ctx.author.voice.channel.connect()
                self.audio_statuses = AudioStatus(ctx, vc)
                await ctx.send('ボイスチャンネルに接続しました。')

    # command to play sound from a youtube URL or add to queue
    @commands.command(aliases=["pl"])
    async def play(self, ctx, *, entry):
        """Play music"""

        status = self.audio_statuses
        status.loopMode = False
        queue = status.get_list

        player = await Music.get_player(ctx, entry)
        if len(queue) != 0:
            await ctx.send(f'`{player.title}`を追加しました。')
        await status.add_audio(player.title, player)

    # command to loop play sound from a youtube URL
    @commands.command(aliases=["l"])
    async def loop(self, ctx, *, entry):
        """Loop play music"""

        status = self.audio_statuses
        status.loopMode = True

        player = await Music.get_player(ctx, entry)
        await status.reset()
        await ctx.send(f'`{player.title}`を追加しました。')
        await status.add_audio(player.title, player)

    @classmethod
    async def get_player(self, ctx, entry):
        if entry.startswith('http') is True:
            url = entry
        else:
            search_keyword = entry.replace(" ", "+")
            regex = r'[^\x00-\x7F]'
            matchedList = re.findall(regex, search_keyword)
            for m in matchedList:
                search_keyword = search_keyword.replace(m, urllib.parse.quote_plus(m, encoding="utf-8"))
            html = urllib.request.urlopen("https://www.youtube.com/results?search_query=" + search_keyword)
            video_ids = re.findall(r"watch?v=(\S{11})", html.read().decode())
            url = "https://www.youtube.com/watch?v=" + video_ids[0]
        async with ctx.typing():
            return await YTDLSource.from_url(url, loop=self.bot.loop)


bot = commands.Bot(command_prefix=prefix,
                   description='Relatively simple music bot example')


@bot.event
async def on_ready():
    print('Logged in as {0} ({0.id})'.format(bot.user))
    print('------')
    await bot.change_presence(activity=discord.Game(name=f'{prefix}hでコマンド一覧', type=1))


@bot.event
async def on_command_error(ctx, error):
    if isinstance(error, commands.errors.CommandNotFound):
        await ctx.send('存在しないコマンドです…。')
    elif isinstance(error, commands.errors.MissingRequiredArgument):
        await ctx.send('引数が足りません…。')
    elif isinstance(error, commands.CommandError):
        pass
    else:
        orig_error = getattr(error, 'original', error)
        error_msg = ''.join(traceback.TracebackException.from_exception(orig_error).format())
        await ctx.send("不明なエラーが発生…。")
        await bot.get_channel(チャンネルID).send(error_msg)
        print(error_msg)

bot.add_cog(Music(bot))
bot.run(token)

試したこと

①get_player()を削除して該当処理をplay()の中で処理してみた。→YTDLSource.from_url()の行までは進んだが、そこで処理が終了。
②get_player()の次の行にprint()を記述→実行されたがprint()以降は実行されず。
③デバッグしてみた。→YTDLSource.from_url()の行までは進んだが、そこでステップインを行うと処理が終了。
④YTDLSource.from_url()をコメントアウトし、別の戻り値を設定。→同じ箇所で処理が終了する。
⑤YTDLSource.from_url()だけをplay()の中で実行→③と同じ
⑥スタックトレースを確認→出力なし