Yes, there is currently a bug in the All Star Polar Alignment for the Southern Hemisphere in all the Nexstar+ hand controllers and not just the AVX mount. The older Nexstar hand controllers did not have this problem. If you have a laptop which you can connect to your hand controller, you can try using the PC software version of the Nexstar controller called NexRemote to polar align the mount as a work-around.
The engineers at Celestron have acknowledged the issue and have said that they are working on it (been going for over a year now) and hopefully they will have a fix soon.
You can join up on Team Celestron to get beta firmware updates when they are available:
http://teamcelestron.com