I guess whatever causes this isn’t happening everywhere, as this forum is OK.
If you need help tracking down the problem or testing fixes, I’d be happy to assist any way I can. This issue is affecting the forum I run. I’m technical enough to have made some Discourse plugins and poked around on the database side fixing another attachments/import issue (although it’s not my bread & butter), so I’m happy to help if the combination of someone technical with a live system that has the problem is useful.
(No problem if it isn’t needed, of course! I don’t know if it’s a rare problem or something easy to reproduce.)
Perhaps the CDN we use on Meta (Fastly) is doing something different and preventing the bug…so it’s not that CDN is causing the issue (or Leo wouldn’t see the issue), but that the unique CDN here stops the bug.
It seems another aspect of this is that attachments which contain plain text will be displayed by the browser instead of being downloaded.
We used to be able to left-click them and they’d download, but now we have to use right-click > save-as to do that.
To see what I mean, go to this post on our forum and click either of the Sort Tabs.dcf or Sort Tabs.js.txt download links in the first post. Both contain text data (the .dcf is XML and the .js.txt is jscript), and you’ll get a screen full of that instead of a file downloaded if you left-click.
(Checked with both Chrome/Windows and IE/Windows in case it was a browser change.)
Edit: I think the download counts are no longer updating, either. Seems as though the whole of the download processing stuff is not happening when downloads are clicked.