What triggers this issue?
This issue reports the URLs from the website’s sitemap files that took too long to respond to our crawler's request.
Why is it important?
Sitemap files of a website must only list the pages of your website you want search engines to crawl and index. Besides, Google uses sitemaps data as one of the factors when selecting canonical URLs.
Search engines will not be able to access (and thus index) the pages that timeout. This can result in search engines ignoring your sitemaps, which can bring up some indexability issues on your website.
How to fix it?
The timeout error can be caused by server issues. You might need help from your web developer or hosting provider to find the root of this problem.
Also, website URLs can timeout during the crawl if the web server is not able to handle the request frequency from the crawler. If you can access the reported URLs in your browser, slow down the crawling speed in the project settings and run a new crawl.