.more-topics__container .nav li .btn { /* Private messages "Related" and "Suggested" selected border was intruding into elements below */
padding: 0em .65em;
}
I suspect that the issue has something to do with very specific font size and/or font scaling settings at the OS level. I saw something similar with this bug report:
The difference in this case with the “Suggested” or “Related” border is that changing the zoom level and/or my OS text scaling value to normal defaults makes no difference.