Post count: 1827

Sorry, I did not think about this before. You need to disable the controlblockservice before this test. You can simply do this with these commands run from within the ControlBlockService folder:
sudo make uninstallservice
Does the output of sudo i2cdetect -y 1 look different then? If the GPIO expanders are recognized correctly, we will see a line
20: 20 -- -- -- -- -- -- 27