Remove the grey selection box in view mode
In view mode (not edit mode) the grey selection boxes show the current / selected symbol. When you start layering symbols or use hidden symbols, that becomes quite useless for the user and can cause confusion. The purpose of showing the selected symbol only makes sense when the symbols allows e.g. keyboard input. And even then the user interaction is doubtful.
Please remove the grey selection boxes in normal viewing mode.
The selection boxes can be used to add data items to the ad hoc workspace starting in PI Vision 2019.