I use user edition. After upgrade to 5.9 kwin window decoration disappeared. Upgrade to 5.9.2 didn't helped. I deleted .config/kwinrc but no improvement. What can I do? What more relevant data can I provide?

I purged neon user and installed dev stable and added new user account to be sure that it is not about settings. But the bug still is present. Maybe it has something to do with nvidia in relation to kwin?

After sudo apt full-upgrade
I get:
following packages were stopped
 libxkbcommon-dev libxkbcommon-x11-0 libxkbcommon0

I reported a bug
https://bugs.kde.org/show_bug.cgi?id=376605
No attention from Neon team?

Does anyone else has this problem?