Sorry to hear about the issues.
Here is a thread about the wifi: iodeOS wifi connection issues
As of now, the fastest way to get this resolved may be to upgrade your router.
As for optus, the device shows that it’s officially supported. See the post here how to verify: BraX3 Telco Compatibility – Rest of the World - #4 by plamen
I suggest that you reach out to Optus directly with that information and try to find out what could be causing an issue.