I have the same problem. Even in playground and test app from openai.
type:"conversation.item.input_audio_transcription.failed"
event_id:"event_AKoGWufao75TYukE7hQsf"
item_id:"item_AKoGT6tHPUsFUJo64bdVg"
content_index:0
error.type:"server_error"
error.code:null
error.message:"Input transcription failed for item 'item_AKoGT6tHPUsFUJo64bdVg'."
error.param:null