@Thisengineburns if you’re using Manychat’s Live chat, it will automatically pause automations when you engage with the specific user - so the default reply won’t trigger.

If you’re using your Meta inbox, then it’s not possible to automatically stop it unfortunately.

Here’s some extra info about Manychat’s Livechat feature: https://help.manychat.com/hc/en-us/articles/14281070478748-Manychat-Live-Chat-Overview