NPN proximity sensor with 7i76E

Happy New Year.

I was unable to find PNP proximity sensors in the form factor that would fit on my CNC to use with my Mesa 7i76e as homing switches. I ended up getting NPN sensors and I setup 2.2K 1/2W pull up resistors  on the corresponding input pins. Everything seems to work fine when I look at the values of the pins/signals in Hal show however the LED on the sensors is always dimly lit when the sensors are not active, they get bright when something is detected.

I guess this is because there is a voltage difference between the voltage input on the sensor and the voltage divider created between the pull up resistor and the Mesa sinking input 20K resistance to ground. So I think a little current is flowing through the sensor output causing the LEDs to be dimly lit. Is this small current flow going to damage the sensors?

I have another type of NPN sensor (low profile) that I plan to use for a bit length probe and that seems to behave normally(the LED is off when no object is detected), so I’m not sure why the other NPN sensors are behaving this way.

I think too that the voltage difference is causing the LED to lit up, although it may look skatcy i think that it won't damage the sensor in the long run as even though you power the 7i76e with 32V the internal 20K resistor is going to limit the current a lot, for example at 32V it's going to sink only 1.6mA that is not going to damage anything, at least not the 7i76e i think. The LED glowing dimly in the other NPN sensors maight be caused by a leaky or not right zener diode in the sensor circuit as it could give a high resistance way to ground for the LED causing it to lit up dimly, or maybe the input voltage is too high for the sensor.

(The next picture is taken from internet, the LED should be the one in series with the 47K resistor i think)
https://lh3.googleusercontent.com/proxy/-q4Y6KTCYu0V-eYYGvh7Zv02upi0BxD_Uv3yKTqw2ebh8ewtXfXn0E2OB-7waRSoSjfZDsXMdN6tficZ-RE5RNB0h4k_TmwP303p-7CdoRe1mc_wQlOuCdGeU41sZrse3X4m4laVMA5pY_SNIvoq-vPUYjZwVyyvOhrJ8g