It looks like a Google thing... Playing with different user agents, seems like Google is punishing old browsers and any version of Opera.
This is the user agent being sent by Opera:
Mozilla/5.0 (Windows NT 6.3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.81 Safari/537.36 OPR/45.0.2552.812
This is Chrome:
Mozilla/5.0 (Windows NT 6.3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/59.0.3071.71 Safari/537.36