All my Google home broadcast message that is configured thru home Assistant automation/scripts has a prefix voice message " You have a broadcast message from my name" followed by the broadcast message that I have set thru automation/scripts in my home assistant.
Why This prefix message suddenly. (it was not earlier)
This is google and the rollout of the Broadcast reply feature - (ok google, reply) - there is (currently?) no way to turn it off. The name is prefixed for all tts google home broadcasts (but not afaik for straight voice broadcasts, as you can presumably recognise the voice)