Great feedback. We agree that it can be frustrating to have a Greater Rift Guardian spawn in a location that is unclear or unspecified, especially if you’re running down that timer. Right now, if a Rift Guardian spawns on an undiscovered part of the Rift map or at certain distance away from the player, sometimes the indicator will not appear. Though technically not a bug, we still want adventurers fighting the Greater Rift Guardian and not the Greater Rift map, so we’ll be working to improve this functionality (ideally making it easier and more consistent for players to see where a Greater Rift Guardian spawns) in a future game update.

With this, we’re also looking at tuning and improving the AI that determines where a Greater Rift Guardian can spawn to begin with.
[Post edited one time, last edit by Lylirra at September-30-2014 7:09 PM PDT (8 years ago)]