Bio-metrics reader stopped working after screen change

Hi. I own a repair shop and repair these quite often. Yesterday I replaced a screen and the customer left happy with the finger print reader working all night... But this morning he wakes up and his fingerprint wont work and the app for it was grayed out. I reset the settings and upon turning the on reader again it gives me an error message like a failed attempt to record the new fingerprint. We reset the device back to factory settings and now the fingerprint app is missing from the settings all together. The option for it has completely disappeared.

He said he researched it and some people were complaining of this happening after the last update that he did 2 days before he came to see me... Any ideas? I do not want to buy this guy a new phone for what seemingly is a software issue. There is absolutely no signs of physical damage to the button, flex, or plugs.