I have been using CloudFlare (free tier) for many years. My use case is to primarily cache a Wordpress site and a collection of .zip files for distribution to my users.
I have seen good caching performance, both for requests and bandwidth throughout the history of the account, but there has been a dramatic change this month (November 2019) and the very end of last month (October 2019). Needless to say, I have made no changes recently to the origin hosting or to the CF configuration.
Here is a recent request graph - the left hand side of the graph shows typical performance, as has been seen over the years. The right hand side demonstrates the drop-off in caching performance, which is getting worse daily. Looking at the trajectory, this is going to end up with very little caching by the end of November.
The bandwidth graph shows an identical pattern, but as a new user here I can only put one image in a post.
Does anybody have any idea what is going on here?