The same problem with Yakuake:
Shift + Ins works, it makes "paste" Ctrl + Ins doesn't work. Appeares "5~".
Taking in account, that Yakuake just a wrapper for Konsole, I checked combinations there and they works, as expected.
Before update from KUbuntu 16.04.4 to 18.04 all works fine.
The same problem with Yakuake:
Shift + Ins works, it makes "paste"
Ctrl + Ins doesn't work. Appeares "5~".
Taking in account, that Yakuake just a wrapper for Konsole, I checked combinations there and they works, as expected.
Before update from KUbuntu 16.04.4 to 18.04 all works fine.