Python Tkinter application. GUI elements not showing

[gentle spire]

I'm encountering an issue with a Python Tkinter application where the "New Project" button click is not functioning as expected. The expected behaviour is to show a data entry frame and populate it with a tree view upon clicking the "New Project" button. However, the frame remains hidden, and the tree view is not updated.

Relevant Files:

project_view.py
app.py
Observations:

Button clicks are being registered, as evidenced by print statements.
The visibility state of widgets is not updating correctly.
https://pym.dev/p/256s5/
https://pym.dev/p/2qb8d/

[tight plume]

can you try calling the .update() function on the Tk() object when you're updating the visibility?