GPIO sysfs interface controls only the GPIO peripheral not the pinmuxing, that’s why it will be available for all gpios not in use by kernel. If you want to use a particular pin you’ll have to make sure that it’s muxed appropriately in the devicetree. if you just want to test GPIOs, some (like pins 133 (linux gpio no. 58) and 127 (linux gpio no. 58) of the colibri module) are already muxed as GPIOs and can be used without modifications to the devicetree.
pin 23 of X1 is SODIMM_23 not SODIMM_142. gpio5.IO[14] in linux has an id of 142. I just checked it with our latest BSP and it works as expected.
Are you using custom image? What carrier board do you use?