Bot being disconnected from chat server

I have a bot that listens to a large number of chats. It appears to be disconnecting from the chat service and not being able to reconnect.

I have contacted Twitch to try and get the bot verified thinking this was the issue, but they say my bot is not big enough?

I am using tmi.js

I split the bot to 3 instances, each listening to a maximum of 50 channels but this has not remedied the situation at all.

I am not getting any helpful error messages from tmi.js with the only message being a repeated Not connected to server.