Let me take a total shot in the dark. The country responsible starts with a C and ends with a A.
They scream cyber attack every time any of their services see a small uptick in usage, like the social services website Centrelink did, when the lockdown/ job losses started. I'm going to assume it's incompetence on their side, for now.
EDIT: 95,000 users is all it took, apparently: https://www.itnews.com.au/news/minister-backflips-on-mygov-d...
Some further information here: https://www.cyber.gov.au/threats/advisory-2020-008-copy-past...
[0] https://www.cyber.gov.au/threats/advisory-2020-008-copy-past...