While the CPI for June 2020 quarter is -0.5%, the CPI for July 2019 to June 2020 is +1.5 (being +2.0 for the first 3 quarters and -0.5 for the last). This is a year in which we had a COVID 19 Level 4 lockdown. So savings account interest of +1% did go backwards and the gap will worsen as the CPI is not affected by negative quarters.
Yeah, that's what I said above - annual inflation to June was +1.5%. But three of those quarters were pre-COVID, so we're only seeing the affects from the June quarter, which is -0.5%.
Having said that, I guess for a saver the damage was really done post-GFC, when savings rates did their big falls.