From what I can see (without troubleshooting this deeply on a PA), it could be because of something called "Extended Master Secret". As the webserver behind your mentionned website is a windows server this might be the reason as I have seen this reason for failed decryptions only on windows servers so far. Other things that might be a reason I cannot see in the webservers TLS configuration.
But to be sure you probably need to dig deeper (or open a support case and let PaloAlto do this work ;)
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