Using Advanced Download Manager app with Android 7.1.2

[Android Central Question]

I have TV box running Android 7.1.2. I recently installed the Advanced Download Manage app (ADM) from Google Play store and am using that to route all downloaded files to the Sandisk SD card I have in the box. I can get the files to save on the root directory of the SD card but cannot configure the system to place the downloaded files in a a Downloads folder I have created on the SD card.
The ADM developer said he couldn't find solution and asked if I had tried another download manager.
I then tried the Uget Download Manager, also from Google Play Store, and got the same problem.
The only difference is that with Uget the system returns a message that indicates I need to set the permissions for the Downloads folder. When I try to access the folder to do this nothing happens and the files still get downloaded to the root directory of the SD card.
I originally thought this was an ADM problem but now think it could be an Android operating system problem.
Any ideas on a possible resolution ?

 

[Rukbat]

Since KitKat (4.4.2), only apps that create a folder can write to it. (That's standard Linux, unless you, as root, change the folder's permissions.) So 1) Android isn't an operating system, it's a program (Dalvik) running in Linux and 2) you could call it "an Android problem", but Google did that deliberately (to keep apps from saving files all over the place) so I don't think they'd consider it a problem. (I do, but I have my SD card set so that everyone [meaning all apps] can write to it. [The phone has to be rooted to do that, and you have to change a system file.])