ChatGpt reports that it can not access some URLs on my site

Some URLs on my site it can access , but others not. When I ask chatgpt for reason it indicates error in fetching the page. It happens for all pages based on a specific page template only. Server side there are no restrictions for this page type. Any idea what could be the problem? The web pages that it can not access are actually smaller than the ones it can access, so that does not seem to be a problem. This problem is not temporary but ongoing for a long time.