Hi ​@rinchen ,
One possible cause might be a flow with smart delay, and in the meantime, an agent sends a manual message, which pauses the automations. There might be some logic in the flow involving the use of smart delays.
If that’s not the case, I suggest opening a support ticket, as delays usually only happen if they’re configured somewhere in the flow.

https://help.manychat.com/hc/en-us/p/get_support_page