Many times you can solve this by using a wired connection to your network. WiFi is always slower than wired. I have resorted to alt, control, delete to get out of an upload that won't finish. Connect with wire and restart your computer.
Often the speed is better if you update late at night. To check your speed, go to the speedtest app.
Sometimes you have to turn it off and take it somewhere with better WiFi speed. Even if it is a public WiFi. It is only updating the program and not your personal information.
In my experience, getting faster internet speed has always resolved this.
You can also manually update TurboTax.
Manually Update TurboTax for Windows Software (Bas... (intuit.com)
