I already know it i think, its cause of after the 24 hours the bot does not response right? 

u Can’t wait more than 24 hours  

I joined this community to ask this question - thanks!

I’m confused though, why offer the option for longer than 24 hours if the bot will not actually send it?

The bot will send messages within the 24h interaction window, that is, UP TO 24H later. If the delay ends 24 hours later, it will send a message at least 24 hours later + 1 second, that is, it exceeds the limit. The ideal is to have a delay of no more than 23 hours

or you can request the md list beta to be able to send messages to subscribers after 24 hours