Who replaced the screen @dgrundy ?
If Samsung then go back to them for support.
If a repair shop then go back to them for support.
If by you or an unauthorised person then the warranty is voided so Samsung wouldn't probably be able to help unfortunately.
I wish you all the best with this situation.
Current Phone ~
Samsung Note 20 Ultra 5G SM-N9860_256Gb SnapDragon 865+
Samsung One Ui 3.1/ Android 11.
I've recently had the same issue.
I broke my screen and replaced myself with a genuine Samsung Amoled screen.
I was subsequently unable to use biometrics to unlock my device.
I deleted the old fingerprint and tried scanning new fingers.
These always failed at 35% and never progressed further.
Only workaround that I've found that returns functionality is to install
Samsung Android 9 firmware and block future updating.
It appears that in android 10, screen and F.P. sensor serial numbers are checked and if either is not Original Equipment, it disables the functionality of the baro reader, irrespective of if the replacement is a Samsung genuine part or not.
As stated earlier, Android 9 doesn't perform this check.
Hope this helps anyone who was baffled by this issue as I was for a few days
Dave, (a now happy A70 owner with a fully functional Fingerprint Sensor) Just a shame I'm locked to an early Android OS