Momentary contact switch not working with Qubino Flush Shutter

Hello! I just installed a new Qubino Flush Shutter ZMNHCD3. It paired right away with my SmartThings hub using the mobile app. I can open and close my curtains with my phone just fine, but the mobile app reports a network server error. When I try to open or close the curtains with the momentary contact switch, nothing happens most of the time. After running the calibration, the momentary contact switch worked briefly, but then stopped again. I’m not sure what’s going on. Any suggestions? Thanks!