Debasement is the Mother of Inflation, page-129

Australia's increase of the money supply ( method ) definitely caused inflation.

The Australian government stimulus was of a blanket method ie, providing economic assistance to most members of society and companies regardless. Of whether they were or weren't economically disadvantaged by COVID or lockdowns thus increasing consumer demand, the velocity of money.

Japan on the other hand has been printing money for years but it hasn't resulted in inflation due to the window method of stimulus distribution.ie to certain sectors of the economy which it will benefit without increasing consumer demand. Increasing money supply through quantitative easing doesn’t necessarily cause inflation.
If the economy is close to full capacity, increasing the money supply will invariably cause the expanding money supply