AI Voice changing accents

I have been using the same Australian voice in my Rise 360 content since earlier this year.

Australian Steve was perfect in every way. But now when I attempt to generate speech from a block of text, Steve somehow comes out sounding like American Steve.

The settings are 100% identical in each case, yet one generates as American and one as Australian which is the one I want to use.

Has anyone experienced anything similar and know how to fix it so my Aussie Steve can talk through the slides to my audience? 

Thanks!