This one’s expected behavior.
o4-mini is a chat-only model and Make won’t output text unless you read it from Choices → Message → Content, unlike gpt-5.2 which auto-maps a text response.
Nothing’s broken, you just need to map the correct output field when using 4mini.
You just need to read the response from Choices → Message → Content in the OpenAI module, that’s where o4-mini puts the text. Once you map that field into the next module, it works the same way as the other models. I tripped on this too when I first used o4-mini.