Hi David, there's no bug report for that in the KDE issue tracker (but in our custom one). I adjusted the patch description above. Is that ok for the kind of documentation that you want to have? (I would prefer to send you a new git-patch that contains a complete description, but phabricator seems to drop any patch descriptions...)

Thanks David for reviewing that. Oh, I already tried to find the underlying bug that causes the inconsistency. The debugging led me from libkscreen to xrandr to libxrandr (XRRGetOutputInfo) to the kernel. Here I noticed the following things: