Wait for Download: The {file} was found but it's in use

I have created a library to use the Save As download screen (screen shown in capture).
This works perfectly when downloading most any file from the web. However, in this case, the website (constructed in Java) is forcing me to open the pdf first, which automatically opens Acrobat Reader, then save the file.
By doing a Save As command from Acrobat, and then selecting “Choose a Different Folder” I get the “Save As” screen indicated in my screenshot - this is good. But when I actually click save, the Wait for Download activity downloads the file but then throws the exception “Wait for Download: The {file} was found but it’s in use.”
I know this is due to the open file, but I don’t know how to get around it.
using Studio Enterprise v. 2020.10.2