The example echobot fails to send messages to some group chats (and maybe some private chats too). In general it is safe to use 32 bit signed integer for all integer types as notet in the telegram bot api description. However there is one exception, that is the chat ids, which may use up to 56 bits (https://core.telegram.org/bots/api#chat). The telebot library also uses 32 bit signed integer (int) to store these chat ids. Apperently thats the cause for those random failure to send data to a chat.
The example echobot fails to send messages to some group chats (and maybe some private chats too). In general it is safe to use 32 bit signed integer for all integer types as notet in the telegram bot api description. However there is one exception, that is the chat ids, which may use up to 56 bits (https://core.telegram.org/bots/api#chat). The telebot library also uses 32 bit signed integer (int) to store these chat ids. Apperently thats the cause for those random failure to send data to a chat.