On AAWireless devices which have been bought on or after 1 September 2022 we only provide support for phones on the official list of Google: https://support.google.com/androidauto/answer/6348019?hl=en#zippy=%2Candroid-auto-on-your-car-display-wireless. This means we only support Xiaomi phones on Android 11 and higher.
We could not get the following solution to work ourselves on a Mi9T. So may or may not work for you.
1) In the WiFi setting, all options must be active. See below screenshots
2) In developer options the "mobile data always active" option must be active.