"Download As..." files vanish?
Hi everybody. I have a pretty stable High Sierra setup. But recently discovered that while on some websites, when I "download as..." to some folder or volume, the file does not in fact download. When the window to the folder is open the downloading file briefly appears and then vanishes. I have tried this multiple times with the same result. I am really annoyed that perhaps dozens of prior files I had assumed had downloaded properly never did.
Its not the source material or source website, because if i do a *regular* download to my downloads folder, it works fine. But I hate having to do that and then move stuff manually to the right place. Its a lot of extra steps that I normally dont have to do.
It *appears* that this may only happen if I am in a private window? and its only some files. Like I can do a "Save image as..." and it works fine. But a "Download file as..." or "Download Video as..." won't. They will only save to the downloads folder.
Is this a permissions issue? I can't figure this out. why would downloads be allowed only into the downloads folder for some files in some cases? And why is there no feedback or warning that it didnt happen? Why does it seem to start and then abort and vanish without a trace?
BTW I have searched for some test files to see if they were invisible, or in a cache or something and no results. If anyone has any advice on this, lemme know.
Thanks!
Mac Pro, macOS 10.13