Native Fields in Custom Forms not working as they do in the Overview

[#1]

Description - The native fields of Portfolio and Program do not work the same as they should in the custom form as they do in the Overview. 

Why is this feature important to you - We need our PMs to select the Portfolio and Program for each project, so we added the native field to our custom form and made it required for them to fill out. Otherwise they miss doing this in the Overview of the project.

How would you like the feature to work - Having the native fields of Portfolio and Program to work exactly like they do in the Overview. When you select a Portfolio, only the Programs for that Portfolio will be shown to select from. 

Current Behavior - Right now, when you select the Portfolio in the custom form, ALL of the Programs are listed. The PMs have to then search and scroll for the right Program. They can also select the wrong one, which they won't know that they did since it allows them to select any Program instead of the ones that are associated with the Portfolio. 

[#2]

Forms keeps crashing for me.