It seems that custom GPTs default to a system chosen voice and there is no way to control that when accessed through the ChatGPT app and irrespective of the voice chosen by the user in their ChatGPT Appp settings. It would nice to either respect the overall voice setting of the ChatGPT app or even better to allow specification of the voice in the configuration panel of the custom GPT so as to be consistent with the overall “persona” of the custom GPT as imagined by the creator.
I have the same case as i have been trying to change it even by command, however the “default” voice is there. Most likely this is not yet available and hopefully soon they may update.
It looks like this is a bug that causes it to ignore your selected voice and choose Ember by default. If you exit the conversation and go back into it from your history, it correctly uses your chosen voice.
I’m having the same issue, and it doesn’t resolve for me if I exit the chat and come back into it.