CTRL-TAB word completion does not work

[Alf HP Lund]

My system is Kubuntu 20.04 with Ubuntu Studio installed on an HP ZBook 15 G3.

In Libreoffice Writer, the cycling through word completion suggestions with CTRL-TAB doesn't work - instead it inserts a tab stop as if I only hit the TAB key.

Other keyboard shortcuts involving the CTRL key, like CTRL-S, CTRL-V, CTRL-Z, etc works as expected.

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: libreoffice-writer 1:6.4.6-0ubuntu0.20.04.1
ProcVersionSignature: Ubuntu 5.4.0-70.78-lowlatency 5.4.94
Uname: Linux 5.4.0-70-lowlatency x86_64
ApportVersion: 2.20.11-0ubuntu27.16
Architecture: amd64
CasperMD5CheckResult: skip
CurrentDesktop: KDE
Date: Mon Mar 29 09:31:41 2021
InstallationDate: Installed on 2021-02-07 (49 days ago)
InstallationMedia: Kubuntu 20.04.2 LTS "Focal Fossa" - Release amd64 (20210204)
SourcePackage: libreoffice
UpgradeStatus: No upgrade log present (probably fresh install)

[Alf HP Lund (alf-c)]

I tried upgrading LibreOffice to the latest and greatest (7.1.1) through https://launchpad.net/~libreoffice/+archive/ubuntu/ppa but the problem persists