Hi klowe22,
Based on your description, I know your Exchange server is using private IP, then mapping it to public IP.
After change public IP address, you should point "mail.yourdomain.com" and "autodiscover.yourdomain.com" to your new public IP address，then make sure this public IP address is mapped with your Exchange server‘s private IP.
Could you ping "mail.yourdomain.com" and "autodiscover.yourdomain.com" successfully?
If you could ping them successfully, could you provide a screenshot about the result of Microsoft Connectivity Analyzer, plain text is hard to read.
Just need to provide screenshot about the result of testing for "https://autodiscover.yourdomain.com:443/Autodiscover/Autodiscover.xml", like picture below(Mainly force on the steps which failed, remember remove domain information):
Regards,
Kyle Xu
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