Cloudflare sending traffic to an old CNAME record

We send analytics data to a CNAME record we setup in cloudflare which is pointing to an AWS Cloudfront endpoint .

events.example.com -> [AWS CLOUDFRONT ENDPOINT 1]

The problem:
We recently updated our Cloudfront endpoint and are still seeing a large percentage of our traffic getting routed to the old CNAME record. I have tried purging our cache and disabling ARGO without luck.

Any idea how to get this fixed?

Do you use CloudFlare as DNS Service only or is it proxied through CloudFlare?
In other words: is events.example.com covered by the orange CloudFlare sign or by the grey one?

CF%20-%20Kopie

If you use DNS Only this is normal as the Clients which called the site (befor you changed the CNAME) will have the IP of the old CNAME cached.
New Users will have the new one.

If you use it proxied they can just cache the CloudFlare IP which results in a always fresh lookup (behind CloudFlare). As soon as you switch something it happens immediately for everyone!

But mind this: if using it proxied the TTFB will be delayed by about 2-5ms (if routed through the nearest POP

Thanks! We have always Proxied the endpoint so we should be getting a fresh lookup as you say.