That looks like it's not picking up a custom variable for uxt-os-bar-height.
Have you also installed Atlas Core and Atlas Web Content module from the Marketplace? Have you also replaced the content of the file ./theme/web/custom-variables.scss with:
@import '../../themesource/siemensinsightshubwebcontent/web/custom-variables.scss';
Also make sure that within your project settings, the Siemens Insights Hub Web Content is after the Atlas modules.
I hope this helps. Good luck!