Tooltip time dont match x axis time

[JPGH325]

Hi there,

I'm trying to figure out why my tooltip time doesn't match my x-axis time.

You will notice that there is no 01:00 on the axis.
The time in the tooltip is the correct one.

Config for the x axis:
xaxis: { type: 'datetime', title: { text: 'Time' }, labels : { hideOverlappingLabels: true, datetimeUTC: true, datetimeFormatter: { year: 'yyyy', month: 'MMM \'yy', day: 'dd/MM', hour: 'HH:mm' }, }, }

Does anyone have any idea how I can fix this?