How to make client keep recieving message after subscribe to the topic?

[iriekun]

I connected to a mqtt server and subscribe a topic. The client is hanging if I don't use mqtt.end() but even if I use or don't use mqtt.end(), the client only receive message once. Is it possible to make client keep listening and keep receiving message from server? I would be appreciated if you can help. Thank you in advance!

[RangerMauve]

Would you mind posting some code to reproduce the issue? :)