I seemed to have found the error. I was using an older version of ChromeSetup.exe, and even though it updated to the newest version, it still had a SHA1 certificate for Google sites for some reason, maybe something built into Chrome?! I don't know. But I went and downloaded the newest ChromeSetup.exe from Google.com/Chrome and the Google websites now show as Secure.
What this has to do with Windows 10 beats me... Nevertheless.. good to see you've found the culprit...
Well after reinstalling Windows, I have this same issue again, on Google, Youtube etc. Downloaded from Google.com/Chrome does nothing, saying not secure.