Fine-tuned 4o errors using the responses API (with image input)

For the past 1 day, we’ve been getting incorrect responses from the responses API. The response keeps spamming an empty array:

{

       "id": "<id>",



       "type": "message",



       "status": "completed",



       "content": [



         {



           "type": "output_text",



           "annotations": [],



           "logprobs": [],



           "text": ""



         }



       ],



       "role": "assistant"



     },

While completely ignoring the specified json schema. The response also indicates no errors, but seems we’re getting billed for the 100k+ tokens it ends up using :)))

Anyone else experiencing this issue? I’m using a fine-tuned 4o model. Not every request has this death spiral though; some do go through correctly.

Edit: I am using image input