Strangely I updated my number on a government website and almost immediately received a call from this number despite not receiving the usual number of spam callers for a few weeks (thankfully).

Like the comment with gov app, soon as I put a Australia gov app the scam calls stared, I just got a new number and I made sure no one owned it before me, no one else has my new number

Most likely a scammer. Phone bumped it straight to spam after the first ring.

I had a call from this number just now, it was silent like other commenters have mentioned, but after about 20 seconds it beeped and started playing music/messages like I'd joined a hold queue. I didn't stick around to find out what was at the other end of the queue.

received call, answered and there is silence. Tried to call it back and its "unavailable"

Silent - likely a hacker.

Answered a call from this number a minute ago but no one replying and I also can't hear any background static noise