I have 4 of these connected to the high impedance analog inputs of a teensy 4.0 microcontroller powered by a 3.3 volt regulator. The voltage seems steady and I have the LED’s dimmed to 50%. The sensors exhibit a jump in voltage as I move a white card slowly toward them with some significant hysteresis. So as the voltage moves down smoothly and gets to about 1.6 volts, it jumps to .8 volts, then smoothly down from there. In the opposite direction as the voltage rises smoothly to 1.4 volts it jumps to 2 volts moving smoothly up from there. Any idea what this is about?