"At 15:45 UTC on July 22, 2021, a software configuration update triggered a bug in our Secure Edge Content Delivery Network impacting that network's domain name service (DNS) system (the system that directs browsers to websites for that specific service). This caused a disruption impacting availability of some customer websites. The disruption lasted up to an hour. Upon rolling back the software configuration update, the services resumed normal operations"
We were affected by this outage indirectly by a third party SaaS application we use but it wasn't a significant impact because it only lasted an hour. What surprises me as more and more companies use DNS protection services is a lack of redundancy in place or proper testing of the update on a secondary system that is near real-time.