Passing value from child to parent - value disappears in parent form after saving child

I have a parent form with a List or Library control set for Dialog editing. I'm trying to pass a value from the child form to the parent, which works until I save the child form. At that point the value in the parent field clears out.

What am I doing wrong? This is part of my code (which I've tried in fd.spRendered, fd.spBeforeSave, and fd.spSaved functions to no avail).

if (parentForm) {    
        fd.field('Title').$on('change', function(ModTitle) {            
            parentForm.field('ModTitle').value = ModTitle;


Dear @boryyytoe,
Most likely some sort of refresh is taking place. It might be better to store values in localStorage while working on child form, and then use List or Library change event on parent form to access localStorage and retrieve these values to parent form - List or Library control — SharePoint forms

Here's how to work with localStorage - Work with SharePoint form fields in JavaScript — SharePoint forms