I just changed BorderlessMaximizedWindows setting in ~/.config/kwinrc to true to hide window title bar and it works, but after restart of my PC my kwin config is reset to default settings, so BorderlessMaximizedWindows is set to false again.
How to make these settings persistent after restart?
Output from inxi -Sxxx:
System: Host: tomsk-U36SD Kernel: 4.15.0-33-generic x86_64 (64 bit gcc: 5.4.0)
Desktop: KDE Plasma 5.13.5 (Qt 5.11.1) dm: sddm,sddm Distro: neon 16.04 xenial
UPDATE:
The problem was with Latte Dock: Can I have different BorderlessMaximized windows option between different layouts?

