Custom GPT Not Following Instructions / Preview Published GPT Differ

I am attempting to create a custom gpt and am at my wits end. It will get to the point that I have the gpt nailed down and the preview shows exactly what I want. When I publish it, it changes and does not follow instructions even though the preview version worked fine. I even asked it directly if it followed my instructions and it answers “no.” Anybody know what I can do? I have put my prompts into gpt4 and told them to write me the best prompts so it comes out correctly. It just seems the programming is doing what it wants without care. Then after I keep trying to get to work I get limited at timed out for over an hour. Its frustrating to pay for a feature that at this point is wasting more of my time than saving

A simple solution is to take the correct response that you get in the preview and put that into your instructions as an example of how you want the GPT to produce the output. If the output is too long for the 8000 character limit, add it in a word doc and then reference the word doc in the instructions. Making sure to quote it as follows “Word doc title.docx”.