I'm not sure I follow exactly how you have this plumbed, but are you trying to use two outputs from the valve? If so, one is typically larger than the other and is designed to go to a spout. Because that spout is essentially full-flow, no water goes to the other port, since it is higher, and usually restricted (showerheads are flow restricted to 2.5gpm by codes). A hose to a handheld is not full flow, so there would be some restrictions, and you may get water into both. You'd likely need a shutoff, or diverter valve to individually direct water where you want it, or two shutoff valves.