Created attachment 135042 [details]
konsole - bash_profile - mouse

SUMMARY
"Underline files" works well for result of ls command, but if we use grep -n command that bottom part of listed names are not underline after mouse over any of such.
To get this result need to grep file present in current directory which has dozen of matching lines. Requirement is that column with matching lines took up the full height of the window.
I observed that on top only couple (5) of names are underlined and on bottom only last 2 or 3 are underlined. Example of result I attached on screenshot.
I assumed that each name should be underlined in vertical column.

STEPS TO REPRODUCE
1. Define and open bash profile
2. In configuration for bash profile check following options:
Path: "Settings -> Edit current profile -> Mouse -> Miscellaneous":
"Underline files", "Underline links"
3. run for example "grep -n qt *" in directory where is present file which you want to search
4. in result you should get long list - dozen of positions with matching lines in one searched file, where file name doesn't start with path. 
5. move mouse vertically over file name from top to bottom and in opposite

OBSERVED RESULT
on top of list only couple first names are underlined after mouse over each and couple on bottom

EXPECTED RESULT
each of name should be underlined after over mouse on it

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: YES
(available in About System)
KDE Plasma Version: 5.20.5
KDE Frameworks Version: 5.78.0
Qt Version: 5.15.2

ADDITIONAL INFORMATION
$ grep --version
grep (GNU grep) 3.6