On iOS, when you use the Share menu to share an audio file from any app to Telegram (e.g., from Voice Recorder or WhatsApp), the message is not sent correctly.
After you have updated to version 7.3 you may have problems with sending old audio files due to caching. Problems with new filies should not occur
Recording is not sent correctly, appears in the chat with a red exclamation mark.
Recording is sent to the chat, and it's playable.
Observed on iPhone XS Max, iPhone 8. iOS 14.2