Crosshair (and other elements) not visible while in block-edit mode in layout

Dear Forum,

when working in a detail view inside the layout area and in block-edit mode, some general rhino elements disappear, e.g. cursor / crosshairs, selection boxes, and even a line you draw inside the detail view only gets visible after you hit enter. This has nothing to do with layer-visibility settings for the detail view. Everything just works fine inside the detail view until you start the in place block editor…

Hope anybody can help?

thank you,
ulrich.