Links remain active while the bot is running and the file still exists in the storage channel. After a restart, old-style (message-id) links may change — your history always keeps the latest ones.

In a private Telegram storage channel owned by the administrator — Telegram provides the durability, Thunder provides the fast links.

Some codecs aren't supported by the in-app player. Try saving the file, or stream in an external player (VLC/MX Player) via the Stream link.

Reply to the first file with /link <count> — e.g. /link 5 processes that file and the next four.