Wordpress: Increase in average response time (Google Search Console)

We are responsible for several websites with different setups. Since the end of September, the average response time in Google Search Console has suddenly increased significantly and apparently this phenomenon only affects the websites with a Wordpress/Cloudflare setup.

I couldn’t find anything about this on the internet - are there any known issues or other website owners who have experienced something similar? I’m happy for any hint as we are inspecting that since quite a while. Thanks in advance!