I made a simple chatbot using Microsoft Bot Framework and integrated it with Telegram.
He works fine whenever I message him privately but whenever I put him in a group with my friends, he doesn't reply, even when I mention him.
/setjoingroups is enabled, and so is /setprivacy.
When you configured your bot on Telegram, did you make it an inline bot? It's been my experience that inline bots cannot participate in group chats, but can message privately. If not, please open a GitHub issue here and we'll follow up there.