Orange Pi Zero H2+ issues with internal and external pull-up resistor

[Zeko9381]

Armbianmonitor:

http://ix.io/3lqb

I installed the pyA20 library for controlling GPIO, but I can't get the internal pullup resistor to work anymore. I managed to get it working before, but after playing around with other things, it stopped working. I have a very simple circuit going on, with just a light switch and I'm trying to read the light switch using the internal pull-up resistor. I managed to get it working for a few days, but that's it. I gave up and decided to solder on my own 10K pull-up resistor from the input pin to 3.3V. To my surprise, the results were the same, the input pin floated. Everything works fine with an Arduino.

This is all very strange and I hope someone can help me. I'm running all the latest software and kernel.