Hi Philip, thank you for reaching out. The reason this works for some cells and not others is due to the length of your "Project-Summary" token. Each row generates a different response length for this prompt, and some may be longer than others, potentially exceeding the 8000-character limit when placed in a ChatGPT prompt. 
To resolve this, I recommend shortening your prompt in GPT to ensure that everything fits within the 8000-character limit. Let me know if this helps!