What you are seeing is a result of how your process is designed.
The Title value you are seeing is being dynamically generated and created by your process to show you the Change Order and the Description / Group.
Since they all start with CO:12345 when you do a sort they will show in numeric order.
To change this you will have to change the behavior so that the Description / Group is first in the dynamically generated Title so when you do a Sort it will group all CAB Review together.
Unfortunately you are going to have to locate where this is set. It is most likely being set by javascript, either in a pre, or post execution code or in a script operator.
It will reference the Process.UserInstName variable as show here:
Process.UserInstName=Run_Script.scriptOutput;