Andre, now I don't know what prevents the autoplay command but right now the issue seems to be there again. The button option is still enabled as I need to keep the car media controls functional.
What I did was install greenefy, change this settings on development options on Android 12.
The only action that prevents the issue is killing/force stop PA on Android.
Follow the processed command line
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11:41:05.998 PlayerService onRoutingChanged
newDevice=bt oldDevice=speaker
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11:41:05.998 PlayerService reloadPipeline
allowPlaying=true forceResume=false state after reload=2
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11:41:06.443 BTReceiver headset event
connection BT=true am mode=0 Audi MMI 2002
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11:41:06.898 PlayerService reloadPipeline
allowPlaying=true forceResume=false state after reload=2
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11:41:07.502 PlayerService reloadPipeline
allowPlaying=true forceResume=false state after reload=2
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11:41:09.371 PSMediaButtonReceiver android.intent.action.MEDIA_BUTTON
KEYCODE_MEDIA_PAUSE ACTION_DOWN name=Virtual source=0x0 sources=0x301 virt=true repeat=0 actionTime=27796822 sourcePak=com.android.bluetooth isAvrcp flags=0x0 playerState=2
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11:41:09.399 PSMediaButtonReceiver android.intent.action.MEDIA_BUTTON
KEYCODE_MEDIA_PAUSE ACTION_UP name=Virtual source=0x0 sources=0x301 virt=true repeat=0 actionTime=27796851 sourcePak=com.android.bluetooth isAvrcp flags=0x0 playerState=2
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11:41:09.740 PSMediaButtonReceiver android.intent.action.MEDIA_BUTTON
KEYCODE_MEDIA_PLAY ACTION_DOWN name=Virtual source=0x0 sources=0x301 virt=true repeat=0 actionTime=27797191 sourcePak=com.android.bluetooth isAvrcp flags=0x0 playerState=2
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11:41:09.746 PlayerService RESUME
from PSMediaButtonReceiver resumePlaying