Tested on Windows 10 Google Chrome 63.0.3239.132 (Official Build) (64-bit)
Windows display scaling set at 150%
Platform version 6.7.7
The problem appears when the column widths exceed the table width. Ordering the last column fixes the vertical height issue of the header.
The issue might be related to https://youtrack.cuba-platform.com/issue/PL-9097#u=1494865924776
I’ve just checked the dates and it seems like the issue has been fixed in 6.7.8. Please let me know if that’s the case.