Casting death gate in ebon hold takes you to ebon hold instead of where you departed from.
I have a theory. Did you go to a different floor in Acherus? If so, how did you get there? Did you take the teleport or just fly up? It would seem that if you fly up you’ll briefly leave the Acherus zone and it’ll reset the Death Gate departure point. Ever since this happened to me, I’ve stopped flying directly up and started using the teleport all the time. This does not happen all the time, but it might be the cause of the issue.
That is exactly what I usually do since the runeforge is upstairs. I’ll try the teleporter.