starting with the SDK30 release the file component stores files in the ASD - application specific directory (file scope = App), this because Android introduced restrictions in accessing files and directories...
to store the file in shared storage (directory /Download), try to set File.Scope to Shared before saving the file, see also my tests here Test "copy file from assets to shared directory and read it from there" in ai-test - #6 by Taifun
see also the overview by @Anke here
Taifun
Trying to push the limits! Snippets, Tutorials and Extensions from Pura Vida Apps by 
Taifun.