Hi Marcel-
I’m sorry to hear that you had a bad experience setting up your CDN. If you have a moment, can you share a little more about your experience so we can get it all fixed up for you?
First, when you say PageSpeed Insights no longer works, do you mean within the performance widget on your main Performance Dashboard/Admin Bar on the front end?
After signing up for the StackPath CDN, did you have difficulty authorizing the CDN or in setting it up?
Generally speaking, setting up a CDN shouldn’t have any effect on your PageSpeed Insights integration, so any additional information you can provide would be very helpful getting your issue resolved.