Chart generation no longer works in my Assistant?

I have several assistants that create charts as part of their prompt, The last two weeks they have refused to actually create the chart but rather include ‘chart data’.
So instead of the graph that I reequest it will output chart data like this

Very frustrating - since nothing else was changed (same prompt, same data format).

Any thoughts? (This is the same with all GPT-4 models that support code completion).

So nobody has this problem? Or nobody is doing charts as parts of messages inside Assistants?