Gpt-4o-mini-tts-2025-12-15 still truncates final sentences; 2025-03-20 is being deprecated

We also use, and really like, 2025-03-20. Our product is used in K-12 education. We’d prefer to keep 2025-03-20, but it seems that’s not going to be possible. We’ve looked at this truncation issue on 2025-12-15 ourselves. On 50 samples, 5 are truncated. In all cases, the truncation is tolerable. In our sample, it only occurs where there is a very short question at the end of the sample, such as: “… now try converting 2500 millilitres into litres using the same method. What do you get?” " … read the first paragraph again slowly and see if you can find both ages. What does it say?" " … counting up is often easier than taking away when the numbers cross a thousand. Now try 3000 − 700 using the same method—what do you get?" “…you need to find out how old she was when she was sent to France. Scan the second paragraph of the sheet—the answer is in there. What does it say?” “…they stay green all year because the climate is hot and wet, with just a wet season and a dry season instead of four seasons. Does that make sense?” In all these cases ‘what do you get/what does it say/does that make sense’ is missing in 2025-12-15 but not in 2025-03-20. This is odd and a bit frustrating, but not disastrous. Sharing our findings in case they are useful for others. And if OpenAI are still working on this model, then would be wonderful if it could be fixed.