What steps are you taking to download from Google Drive? Do you get any error messages when trying to download? The correct steps are to go to FILE > DOWNLOAD FILE FROM CLOUD SERVICE > in the window that opens select GOOGLE DRIVE from the Dropdown and then click OK, the program should open a browser window for you to enter your credentials for GOOGLE DRIVE (If you haven't already) and then you should be able to select the files to download.
if you have any issues going through this process you might want to try and set a different browser as your default browser and try again. You might also need to change your privacy settings for your google account to allow access.
In any case if nothing works you might want to reach out to the NCH technical support team and have them help you out:
https://www.nch.com.au/support/index.html