I released a Skritt Burglar from a chest located inside the circular tree stumps located northeast of Caledon Haven Waypoint. After chasing and attacking the skritt for 30 seconds, she suddenly remained invulnerable, rendering all hits and shots as “missed” and “obstructed” for the next 60 seconds.
She then teleported to a road east of Lionguard Waystation Waypoint, where she spinned and disappeared.
The Skritt Burglar was running through Willowalk Groves when this happened.
This bug has happened twice since I saw her ran through this path last month.