On my website, ng-grid is as follows:

I found out that this disappears when I manually do:
.ngVerticalBar {
line-height: 30px;
}
Of course, I commented on all non-local styles. So there is only a link to ng-grid.css and my main.scss, but I do not touch the row height.
The check shows that compiling from scss to css introduces the line height: 1.428571429 on the body tag. Commenting this out and checking again, this line is no longer set for this element, but the height is set to 16 pixels, although you cannot see where it came from. Since there
ng-style="{height: col.rowHeight}"
placed in this div, I would suggest that he got it from there.
So, I took batarang and saw that rowHeight was installed on the col object, but no.
So, I think I'm pretty stuck here ...
EDIT: gridOptions.rowHeight 30.