Fingerprint sensor ultra slow after Android P

The slow fingerprint reader and slow screen wakeup bug is only present if you have your Ambient Display set to NOT be always on. Set it to always on, and the reader is fast again.

At least for me.
 
Don't use AOD and works fine for me on a P2. My FPS issue was not having it work much of the time, hit/miss.
Interestingly enough when I put the case back on that issue has so far gone away. So leaving the case on for now, a simple Spigen shell type.