I can't seem to set the pull-up resistor mode on the PI4 with most methods I try. I have tried: C# (the new System.Device.Gpio interface), WiringPi (using a C# abstraction), and wiringPi command line interface. Setting the pin mode to input or output always works, just not changing the pull up mode. If I use an example python script, the mode does change, so the hardware is likely not broken.
Steps to reproduce:
root@raspberrypi:/home/pi# gpio -g mode 24 in root@raspberrypi:/home/pi# gpio -g mode 24 up root@raspberrypi:/home/pi# gpio -g read 24 0 root@raspberrypi:/home/pi#
There's nothing connected to BCM Pin 24, so the result should be 1. Same result with WiringPi 2.50 and 2.52. Same result on other pins.