You would have to install the Shared Ownership App on your account as shown in this solution article.


After this is done, there are two steps involved.


1. Map internal groups to a ticket status:


Go to Admin > Ticket fields 

Excluding the 4 basic statuses of ticket, map the custom statuses under Mapped Internal Groups.

NOTE: Don't forget to include Customer responded.


2. Set up automation rules to make sure everyone's in the loop:


Go to Admin > Automations > Ticket updates tab > New rule


Set up a new automation rule as below:


When an action is performed by

Requester


Involves any of these events

Reply IS sent


On tickets with these properties

Status is NOT > Open OR Waiting on Third party OR Waiting on Sellers team


Perform these actions:

Set status as > OPEN

Send email to Agent > Assigned Agent