When you mention Support, is that Mailgun or Cloudflare? Can you check your Mailgun events log after sending your latest blog?
There seems to be an issue with CNAME because Mailflagger can see all the other email events. Cloudflare forum mentions turning off the orange cloud for CNAME. This appears to bypass Cloudflare. And if it is off, try turning it on and off to make sure setting takes. Have you tried this yet?
With your permission I’d like to send some test emails from your Mailgun account using Mailflagger. Would that be ok?