Custom App (MCP) not working with GPT 5.4 pro, only with regular GPT 5.4

Hey @Tristan_Morris! Yeah, I get the mix-up This is what’s happening at the moment: Apps, Memory, Canvas, and image generation aren’t available on the 5.4 PRO version, which is why you’re seeing the difference compared to Instant.

You can also review this helpful article for more clarification: GPT-5.3 and GPT-5.4 in ChatGPT

-Sunny