Currently for me, there is a zone marker showing the Grant Hunt is in Thaldraszus. The wowhead front page says it is in Thaldraszus.
I went there and I cannot find any indication of a hunt being active.
Can anyone explain how this damned thing works, because it keeps happening and it bugs the hell out of me. 
There’s only 2 spots it can be in Thaldraszus, one at my location, and one at the location its currently up now. I believe the other zones have 3 locations, and I’m pretty sure they always rotate in the same order with one always being up at any given time.
If you set tracking in the bottom left to Maruuk Centaur, it will highlight the icon to make it easier to see.
I left the zone and came back in and the marker had shifted to the one you show. So I appreciate the help but the markers are still very confusing.
There’s a marker on the world map that simply shows that the grand hunt is in a specific zone and does not have any bearing on the current location of the hunt inside that zone. While zoomed into a specific zone, the marker will shift to the location of the currently active grand hunt.
Yes, but there was no other marker on the Thaldraszus map when I got there. Nothing but the Rift marker. After I left the zone and flew back, the hunt marker was there. It was almost at an end so I was lucky to get to it in time.
Did you fly through valdrakken?
They have always been kinda finicky. They won’t show up on the zone map unless you are actively in the zone. Keeping the map open as you zone in does not let it refresh so need to close and reopen. If you were in Valdrakken then that also would not show the Thaldraszus hunt since it’s not the same zone map.