Looking at your bots, I see they are still connected to Telegram, and their messages per day have not changed, 1,865 messages yesterday.
Are the groups supergroups or normal groups? Bot Libre does not allow bots in supergroups to avoid spam.
Check if the bots are still subscribed to the groups in Telegram, and ensure they have not be banned by the group.
Can you email firstname.lastname@example.org with:
- the names of the bots on Bot Libre
- the names of the bots on Telegram
- when they stopped replying to group messages
- the list of groups they are currently subscribed to in Telegram
- are the bot's group admins