Nightmare map scry gone

I had nameless seer spawn in Fortress map and I put the scry onto Dunes. I was levelling a new character and I noticed that they scry was gone. I logged on to my main and it wasn't there.

Things that led up to disappearance:
- Logged off
- Logged in to a character in standard and deleted it
- Completed campaign with new character
- Removed voidstone from upper right quadrant

Based on other bug reports, it could be any one of these.

The same happened to me, logging off seems to be the issue, as I didn't do any of the other.