This code works as intended when run alone:

import tkinter as tk
from tkinter import filedialog

root = tk.Tk()
myFrame = tk.Frame(root)
    
def actionTest():
    filename = filedialog.askopenfilename()
    svTitle.set(filename)
    lblTitle.update()

svTitle = tk.StringVar()
lblTitle = tk.Label(myFrame, textvariable=svTitle) 
lblTitle.pack()

btnTest = tk.Button(myFrame, text="Test", command=actionTest)  
btnTest.pack() 

lblTitle.pack()
btnTest.pack()
myFrame.pack()

root.mainloop()

However, when the code is run within a bigger block of code, the label doesn’t display or update text. Please help!