Combining Time series and categories on one axis

Hi Community!

I am trying to plot a chart that has two line traces that need to be plotted over time. Each “value” has an ID associated, so in addition to drawing the lines I want to show IDs on the X axis. This is kind of working with this plot: https://codepen.io/Carnageous/pen/jOrJJbR?editors=1010 But I am not really satisfied.
Because I am using “multicategory” as the x axis type, the dates are not plotted properly. Instead it’s showing dates as categories (I guess that’s what it should do here).

Here an example of how the chart looks at the moment:

My questions is: How do I plot a normal timeseries, so with “prettified” dates, but also add those IDs as categories?

Thanks in advance!