@Andreas_Hegenberg When playing a youtube vid. in Show Floating WebView (html inserted). After closing the webview window (by cmd-w or red dot upper left corner). The youtube audio keeps playing. Is this expected behaviour?
I think you are right, there was a potential retain cycles (i.e. the webview not really being closed) with some configurations. Could you check whether 5.489 solves this for you? (uploading now)