Hi @smu44, thank you 
Is it possible to have more details about what modifications you made (and how) please ? (I have no skill in debugging). In case somebody else wants to make an update for instance.
This device is officially supported by LineageOS on Pie so normally everything should work out of the box, no ?
LineageOS support requirements :
All devices with a Fingerprint Sensor MUST support the Fingerprint Sensor if the stock OS supports it with Marshmallow or higher Android versions.