When pressing and holding the mouse in the editor and releasing while holding the Ctrl-button (thus performing a right click) the selection area (the blueish rectangle) will reappear twice when starting a new selection. NOte that this is on a mac.
To reproduce:
· Press and hold left mouse
· Move mouse
· Press and hold ctrl
· Release mouse and then ctrl.
· Press and hold left mouse
· Move mouse
This will be resolved in 3.9