Support will be familiar with typical issues for FoE. In the meantime, to tide folks over with unhelpful tech talk, here are some of my wild guesses:
It may be connected with the one significant, new feature, Battlegrounds. It requires more communication between client and server. Apart from being obvious that it must do so, I've also noticed some teething issues. If so, some techs at Inno is sure to be working on it already.
Australia has a famously temperamental Internet access. It's a mishmash of different technologies working (poorly) together, some of them prone to downtime and lag. There may be an issue with your carrier, dealing with problems between you and them, or, less likely, but possible, them and the wider World. A submarine cable provider experiencing issues could result in unpredictable routing through several continents, which would fluctuate. There are also a number of possible issues with your configuration. It may be anything from issues with your DNS (tends to come and go, and be specific to some sites) to your router (tends to be constant) and more. The gist of it is that it can be virtually anything, most of it having nothing to do with Inno. If others from Australia are experiencing the same lag, you may want to compare notes, especially on providers. You may also want to run some ping tests; there are sites that offer this. If anyone knows the geographic location of the physical .en servers, that would help with the ping tests. I could check, but, unfortunately, I'm lazy.
Short of that, you may need to have a chat with folks in OF; who knows, they may be tampering with Australia's submarine cables. Any enemy guilds consisting largely of OF players are natural suspects.