Power Button acting as home button. Home button no longer working.

After replacing the power button/volume rocker flex ribbon, the iPhone 5 in question no longer has a working home button and the power button now functions as a home button. This also means that the power button is not turning the device off.

I have repaired power button flex cables before and have never ran into this problem. So far I have:

Checked for damage to the logic board and haven't seen any.

Tested the home button flex cable by touching the prongs with screw drivers (it did not work so I assuming this is the cause of that)

Checked the settings and none of the accessibility settings are on that would cause the power button to behave in this fashion.

Any advice on where else to look would be great. Next thing for me to replace is that seemingly unresponsive cable.

Thanks in advance!