What repair did you conduct on the phone? Apple did put a software kill switch on the home button itself if it were replaced, but I havent seen any other repair cause that. However , that being said, I did have a repair end up with no home button function after replacing the screen. I switched to another screen and the issue was resolved. Remember your screen is like the middle man between your home button and the logic board. The button plugs into the screen and the screen plugs onto the logic board. A cheap or faulty screen can contain low quality components that affect the signals your phone and home button are sending. Ive seen this issue once on an iPhone 7 and several times on 6s and 6s Plus models that have the button connector integrated into the backlight assembly. Hope this helps,
Jake