When using tools like the circle or brush a mask is created, the same in spot removal or healing module. By going down to the mask icon it will toggle it on and the yellow mask will show instead of the circle or brush strokes that normal appear.
As I understood the stated issue and why I think what was posted is relevant. Say photo is a tee shot and on the green and there are three pieces of trash. There are two options now, either select the tool ( lets say the circle) place it on the trash and click, by design the tool now defaults back to none selected. If it defaulted back to the tool this would be continuous mask creation. In order to do all three at once now the control key must be held then select the tool and click on each piece of trash. Once the control key is release it will again default back to no tool selected. After creating masks they then need to be displayed to move or edit them, if required.
If I misunderstood your issue I apologize for leading you down the rabbit hole.