@20after4 : Should we (by which I mean not me) report this upstream?

Discovery folks are trying not to mess with the task for now, in case y'all want to do any technical analysis of what's happening. But at some point we'll need to act on the task so it isn't cluttering up the board. Can you let us know when it's OK for us to move it?

This topic sounds like work and not like personal/volunteer activity.

My guess is that this transaction (in September 2016) hit a bug and failed to remove the task from the "Up Next" column in the parent project.

T140289#2629109

We've fixed a couple of bugs like that where unusual moves or tag edits didn't quite end up in the right state, and didn't work too hard to fix things since they're rare and making any additional edit normally puts everything in the right state again.

If so, you probably won't be able to put another task into this state now (since the bug has been fixed).

Unless @mmodell or anyone else wants to dig into it, I'd guess the database state won't help us narrow things down so you're probably fine to move the task into the right place.

If you can find a way to reproduce this feel free to report it upstream, but I don't see anything else in the transaction log that looks suspicious or points at a reproduction case to me, and I think there's a very good chance that this is just an artifact of an older bug.