Heath Hekkers, As I understand you are facing an issue with App Service managed certificate (ASMC), certificate name mismatch (but, the website works fine across different platforms) – Just to highlight, Azure fully manages the certificates on your behalf, so any aspect of the managed certificate, including the root issuer, can change at anytime. These changes are outside your control. Make sure to avoid hard dependencies and "pinning" practice certificates to the managed certificate or any part of the certificate hierarchy.
App Service certificate vs App Service managed certificate (ASMC) - The free certificate comes with the following limitations: See this doc
The free certificates are issued by DigiCert. For some domains, you must explicitly allow DigiCert as a certificate issuer by creating a [CAA domain record] with the value:
0 issue digicert.com.
You may always leverage App Service diagnostics from Azure Portal> Navigate to your App Service app in the Azure Portal. (screenshot below)
In the left navigation, click on
Diagnose and solve problems - Run – “Configuration and Management” and “SSL and Domains” to fetch more info.
Also, see this doc -An App Service is showing the wrong certificate
Kindly let us know, I'll follow-up with you further.