ShowSelection method is working differently in List and Form Applets

We want to write a script in PM on change record event. We are using below line in Init method of PM.

this.AddMethod( "ShowSelection",  SelectionChange, { sequence : false, scope : this } );

We are writing script in function SelectionChange.

The script in SelectionChange is executing always on record change in Form Applets, but in List applets only when the record is edited, this is getting called. If I keep navigating through records without editing anything, it does not call the ShowSelection method. Is this expected for ShowSelection. How can we achieve my requirement in PM.