Sorry to cross post. I put this on the KDE list yesterday but no responses. As I run Kubuntu I thought that it would be a better place to start.
Starting yesterday morning both of my KDE machines no longer show a system title bar or border for Chrome, and only Chrome. All other apps are fine. Right clicking the Chrome tab area has a checkbox for 'Use system title bar and borders' but it does nothing. Chrome version 94.0.4606.54. Losing the title bar means losing (as far as I know) the ability to pin an instance of Chrome to all virtual desktops which I use for browser streamed media - YouTube, Netflix, etc. I've switched that window to Firefox for the time being. As Gentoo is usually a bit further forward I wondered if anyone here using Chrome and KDE has seen this issue? Thanks, Mark