Touch ID not working

So this seems like a common topic in the iFixit community, but here goes:

I am currently in possession of an iPhone 6 which was exposed to liquid. Going through the necessary steps of removing the EMI shields, ultrasonic cleaning, etc. I was able to get the phone up and running. Almost everything checked out, except the Touch ID function.

This is where it starts getting interesting. When I take another Home Button and connect it the the ribbon cable, it gives me the option to "Add Fingerprint", but when I select that option, it states that it failed. I know it would to begin with because it was not the original home button. But when I try connecting the original home button, the physical button works, ie. still functions as a home button, when the option to "Add Fingerprint" is greyed out.

Based on my tests, I can conclude that the FPC and flex cables are working properly. There just seems to be an issue with the home button itself. If anybody has had this issue in the past or has any insight, please share what you can. Any help would be appreciated.