Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
Yes, the recently added @twgs.qld.edu.au school account is probably causing this sign-in conflict. However, it has not replaced or cancelled your paid subscription.
I would need to know though - where exactly are you signing in?
On the app level, like Word, Excel, etc?
Or on the web via web browser?
Please let me know so I can suggest your next step(s) accordingly.