As far as I have been able to tell this is a Google problem, because if I mask my user agent to show it as firefox or chrome using an extension Google shows the new UI

I am using Opera 45.0.2552.881 (PGO)
and user agent is "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.36 OPR/45.0.2552.881"
and using this extension to mask https://addons.opera.com/en/extensions/details/user-agent-switcher-5/?display=en

Also just found out turning on VPN seems to correct this problem