You have mentioned LEDs - but no LEDs are mentioned in the sketch.
My suspicion is that you have the LEDs - of various colours - wired to the switches and given that you specify 17 mA, I presume you have current limiting resistors in series with the LEDs.
Since you have described essentially nothing about your circuit, we can only surmise what is going on. We do not know for example, whether you have the switches to ground and the LEDs to 5V (which is the preferred way to do it), or switches to 5V and LEDs to ground. And presumably, you have the inputs connected to the point between switch and current limiting resistor rather than between resistor and LED.
So the point is, the LEDs when no current is fed to them, do not pull the current across them to zero, but only to the point just below their threshold voltage, which may be as high as 3V or more for coloured LEDs. This is more than the switching threshold of the Arduino inputs which is about half of Vcc, or perhaps 2.5V or so. This means that when the button is open, the voltage does not drop back to the "logic 0" level.
One - but not the only - reason for wiring the buttons to ground and the LEDs to Vcc, is that you can enable the internal pull-ups in the Arduino (by writing the pins to HIGH even though they are inputs) to pull the pin voltage fully (or near enough) up to Vcc to conclusively register a "1". Of course your logic is reversed, but that matters not in the slightest; it is dead easy to arrange the code to do whatever you need it to do.