Hey Google and Voice Match "Unavailable" on this device

[herbie1958]

2018 Lexus RX450h
Vline VL2 upgraded to Android 12 and all updates done
Xiaomi Mi 10T Lite phone, fully updated (only used as a wifi hotspot to give the Vline a gateway to the Internet.)

OK Google/Hey Google used to work perfectly well but it's just decided to give up and stop for no apparent reason. I do not use Android Auto. I prefer to download all my apps directly to, and then run them directly from, the Vline unit itself.

I've watched YouTube videos and Googled for answers but so far been unsuccessful. Everything I've seen or read up to now gives instructions on how to "switch on" both "Voice Match" and "Hey Google" but my problem is that the switch does nothing and I get a message to say that "This feature is unavailable on this device."

Any ideas on how to fix this guys?

[Noeleon]

HI herbie1958 I'm experiencing same issue too, as stated in your post I don't use Android Auto/Carplay either I use solely as an android unit.

Android 8.1 prior to update to Android 12 I used Voice commands for navigation as well as opening and closing any apps I required with a Hey Google/OK Google command.
This resulted in a totally hands free experience on the go as I dont have to remove my hands off the wheel . My phone calls I manage thru Bixby voice commands being a Samsung head so it was a nice little set up.

Any luck an update will get us back on track soon