Are you holding Ctrl? If so, don't. A simple tap will activate the Copy function of the Move tool. This function was updated in a maintenance release of 2021. Read the tip at the bottom left of the screen when you have the Move tool. Notice that a double tap of Ctrl activates a Stamp tool which will place copies of your object wherever you click to drop one.
BTW, your forum profile shows you are using SketchUp 2016. Please update that information.