Routines Not Triggering based on presence sensor

Hello All,
I am new bee to smart things.
I have mobile phone as a presence sensor & it is not triggering when I am away.
I can see it shows away but when I changed my mode to home, I was expecting it to set to away automatically based on my presence is away.
Appreciate any support on this
I am using smartthings classic app

Are you using the SmartThings Classic app or the new SmartThings (Samsung Connect) app?

Wait … so you are setting it to home after it had already correctly changed away? I don’t know for sure, but my guess it only changes when your home/away presence actually changes state. Not like a realtime monitor.

Smartthings classic app