Downloader
Downloads land in the wrong folder. The destination is either the VidVertex inbox (resolved from the main app's settings) or your custom folder — check the Downloader's settings. Without VidVertex installed it falls back to your Downloads folder and says so.
A link needs a login. Enable cookies-from-browser in the Downloader settings and make sure you're logged into that platform in the selected browser.
TIP
There is no second inbox setting to keep in sync. The Downloader reads the handover folder out of VidVertex, so changing it there is enough.