align top of vertical section in communication site
On a communication site, if you keep the hero webpart its top edge is flush against the information bar with the New/Edit/Publish buttons.
If you add a vertical section, the first webpart always has a space above it. For example, try the countdown - it's top is always below the hero top edge.
On team sites I can adjust because if I use a news webpart with a title instead of a hero, a web part in the vertical with a title will line up correctly.