Why doesn't $voiceClient->close() work?

[euna-p]

I’ve implemented a feature where the bot joins a voice channel and uses TTS to read messages aloud.
(I’m using version 10.1.1 via Composer.)

Under normal circumstances, $discord->joinVoiceChannel(), $voiceClient->playFile(), and $voiceClient->close() work flawlessly. The bot can join the channel, speak the message, and leave without any issues.

However, if the bot joins a channel and no messages are processed for an extended period (I haven’t pinpointed the exact duration), calling $voiceClient->close() triggers the following warnings:

[2024-12-14T02:19:38.344885+00:00] DiscordPHP.WARNING: voice websocket closed {"op":1000,"reason":""}
[2024-12-14T02:19:38.344953+00:00] DiscordPHP.WARNING: received critical opcode - not reconnecting {"op":1000,"reason":""}
[2024-12-14T02:19:38.344996+00:00] DiscordPHP.WARNING: voice client closed

After this, the bot becomes completely unresponsive to any voice channel actions.
(It cannot join a new channel or leave the current one.)

Am I missing something here?