Valid certificate but still get SSL errors

Question

Hello,

We have a cert for our site https://www.blocherconsulting.com
If you browse there, sometimes you get the *.azurewebsites.net built-in certificate, like this:
However, multiple sites that check certificate validity return the correct result: https://www.sslshopper.com/ssl-checker.html#hostname=blocherconsulting.com

We've tried various things like flushing the DNS of the client machine, trying it on domain machines, non-domain machines, etc. But a lot of our clients also report that they see this issue.

Why would Azure serve up the default certificate when the certificate is configured within App Service and verified internally and externally?

Answer 1

The issue is your DNS. You have got 2 A records setup for blocherconsulting.com that are pointing to two different IP addresses.

So traffic is going to two different places, one which has a valid cert, and one does not. You need to remove the incorrect DNS record.