Just to clarify, Twitch calls these “chat lockouts.” They occur when you break the rate limits for messages per second.
This would mean you sent 20 messages (or commands) within 30 seconds or 100 messages (or commands) within 30 seconds if you’re a mod of the channel. It is important to note that if you pass 20 messages (or commands) within 30 seconds as a mod and then chat in a channel where you are not mod on the same connection, you will be locked out of chat.