After some clarification via DMs, the issue was that while a file was downloading - it was not the actual installer.
This is because sourceforge requires Wget user agent for a ‘direct’ download that also attempts to grab the latest version.
function Get-BitTorrent {
param (
[string]$URI = 'https://sourceforge.net/projects/qbittorrent/files/latest/download',
[string]$Location = "$env:temp\qbittorrent.exe"
)
$WebClient = New-Object System.Net.WebClient
$WebClient.Headers.Add('user-agent','Wget')
$WebClient.DownloadFile("$uri", "$Location")
}
Defining the user agent in the webclient appears to resolve the issue.