It appears to me as though the message that appears in Chrome 64 dev tools warning of pending distrust is *wrong*. In Chrome canary 66, the same website loads just fine and the certificates are claimed to be valid. I think that the code in Chrome 64 is checking the date that the Symantec CA issued the cert rather than the date when the leaf cert was issued. This makes a difference when the root cert is a legacy symantec CA, the intermediate CA is not listed, and the leaf cert was issued in 2017.
It isn't clear to me which is the correct behavior.
I'm also looking for an example website which has a cert which is distrusted by Chrome 66. Any suggestions?
Philip