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Usually, we are talking about a wrongly coded page, which gives you a loop when crawling. If you can show the site itself, I will gladly help you find it. If you cannot disclose the url, you can do the following: create a crawl with a tool such as Screaming Frog, filter for these URLs, and check their inlinks and anchor texts specifically for this type of URLs. When you will find a pattern, you will find where the code is broken. Good luck!