I will also add, regardless of the JAWS version, I find it far easier to locate things when I am forced to pick their actual save location. I always go in to any browser's settings for downloads and set up the "make me choose each time" option.
In Chrome, that's Chrome Settings, Advanced, Downloads, "Ask where to save each file before downloading" toggle.
Once that's set to yes, you will get a Save dialog for every download, and you can select exactly where you want that file to be saved and be able to rename it to something more reasonable when you get the randomized numbers file names.
Brian - Windows 10 Pro, 64-Bit, Version 1809, Build 17763
Here is a test to find out whether your mission in life is complete. If you’re alive, it isn’t.
~ Lauren Bacall