Created attachment 7546 big-window-jumps-to-left-bad.mkv 1) start any app (e.g. thunar), make its width two thirds of the screenwidth 2) maximize it by dragging the middle of the titlebar to the center of the top 3) unmaximize it by dragging it from the center down 4) the window jumps to left upon unmaximization. If the same is done with window narrower than 1/2 the screenwidth, the window (and the mouse grip) is correctly kept in the center.
Created attachment 7547 small-window-kept-centered-ok.mkv
Created attachment 7548 Keep grip proportionally fixed To keep the distance of the grip from the edges of the window proportional, the grip is always recalculated using pxratio and pyratio during unmaximization/untiling.
Created attachment 7549 0001-Keep-grip-in-proportion.patch Better version of the patch. To keep the distance of the grip from the edges of the window in proportion when unmaximizing/untiling while moving the window, the grip position is recalculated using pxratio and pyratio.
Adam Purkrt referenced this bugreport in commit 315e1bea2f10263c9d3f3d64fb8233abc69b194d Keep grip in proportion https://git.xfce.org/xfce/xfwm4/commit?id=315e1bea2f10263c9d3f3d64fb8233abc69b194d