From Guild Wars Wiki
Update -- May 17, 2018
- Performed server maintenance.
- Fixed a bug when ALT+Tabbing the client in Fullscreen mode wouldn’t mute audio while using the "Mute game audio while the client is in the background" option.
- Fixed a desync when ALT+Tabbing the client in Fullscreen mode for long periods of time would cause rubber banding and teleportation of other creatures and players.
- Note: This was additional improvements on top of the previous fix put in place in the last update.
- Fixed a client crash on exit.