This is because mouse and touch behave a bit different overall.
Mouse can get a position all the time, you don´t have to click.
Touch can get a position BUT you can only get that position when you are actually touching. (How else would that work, there is no "mouse hover" equivalent)
Holding click should work since you are simulating touch. If that isn´t what you want you´ll have to split those up as BadMario suggested.