When opening KDE applications like KCalc, Kate or System Settings I get popups with text like 

'There are two actions (Quit, Quit) that want to use the same shortcut (Ctrl+Q). This is most probably a bug.'

When trying to use the shortcut a new popup says
'The key sequence 'Ctrl+Q' is ambiguous. Use 'Configure Shortcuts'
from the 'Settings' menu to solve the ambiguity.
No action will be triggered.'

When trying to change the shortcut for 'Quit' through configure shortcuts in the menu in KCalc there exist no duplicate.

For example when opening KCalc the first popup appears a number of times for these commands
* Quit (Ctrl+Q) once
* Undo (Ctrl+Z) twice
* Redo (Ctrl+Shift+Z) twice 
* Cut (Ctrl+X) twice
* Cut (Shift+Del) twice
* Copy (Ctrl+C) once
* Copy (Ctrl+Ins) once
* Paste (Ctrl + V) twice
* Paste (Shift + Ins) twice
* KCalc Handbook (F1) twice
* What's This? (Shift+F1) twice

If I remove KCalc Handbook shortcut for KCalcs configuration then that shortcut works as expected
If I Globals Settings Help is set to F1 for shortcut and None for alternate and KCalc Handbook shortcut is F1 , alternate None it works as expected


Kubuntu 17.04 (upgrade from 16.04 with the same problem)
plasmashell 5.9.5