whether there is any option in Appian to vanish Pop up once timer got completed

What kind of popup do you mean?

For both Record List and Related Action we are using as pop up to fill a form or to show minor information. But user have habit of leaving the pop up for very long and then when they come back it will not allow them to take action as timer got completed. Only option left is refresh the entire page which they dont want. Could you please guide me on this problem

What is the exception timer duration you have set and how long is the expected time that the user can leave the form open? For instance, in one of our applications, the client wants to keep the form open, till they log off for the day. So, they asked to set expiration timer to 8 hours which is their shift duration. Please note that this was implemented for a use case where less number of tasks will be active at a time. See if this works for you.

What is the exception timer duration you have set and how long is the expected time that the user can leave the form open? For instance, in one of our applications, the client wants to keep the form open, till they log off for the day. So, they asked to set expiration timer to 8 hours which is their shift duration. Please note that this was implemented for a use case where less number of tasks will be active at a time. See if this works for you.

In our case, users not worry about timers they want this pop up should get disappear if no one taken action