Live AI voice sessions not working (2.5-flash-native-audio-preview-12-2025)

Hello, we are experiencing problems with the Live sessions we implemented in our app. We’re using model ‘gemini-2.5-flash-native-audio-preview-12-2025’ but it doesn’t seem to initiate the conversation, and only responds whenever there is input from the user. We would like the AI voice to greet the user first, before responding to input of the user. We have tried multiple Gemini AI models, but apparently, the 2.5 flash native audio should be the best one. However, we don’t seem to get it to work… Is there anyone who can help us with this? We’d be forever grateful!!