Had a look at
1. The graph in the link that I sent you, which was not fixed
2. The jsfiddle example.
Again, I never wanted only the years to show, but I observed like you were saying that Chrome didn't understand the datetime format.
So I removed the formatting itself, but kept the "datetime" setting from jsfiddle, and it seemed to work.
Went back to my own example, and explicitly set "datetime" as the format of the x-axis in the new user interface. That should be the only thing necessary, I thought. But no, now there is some kind of decimal format showing up, please have a look at https://cloud.highcharts.com/show/S__QgK2mu
in the different browsers again.