Rather than fragmented groups, get your Australiana posting in at the Aussie Zone Communities. No affiliation other than living in Australia.
Has cities, sports, politics so far and will add more as needed. It even has Perth and thankfully no Tasmania.
I’m on lemmy.ml as well, having issues with community discovery for a couple of the communities here (primarily ausfinance). Maybe federation (or lemmy.ml) is having issues due to the server load from all the new users?