Hey @thehansson,
While we don’t officially have a roaming arrangement with Telstra for Cat-M1 we have seen several Novas and other Cat-M1 devices use that network.
Can you try setting +UMNOPROF to 0 and then attempting a connection. Also, you’ll want to make sure that your SIM is on a global plan and not a US only plan.
Cheers,
Maiky