This is my post from October 10. Since then I haven't have any lag whatsoever. Yesterday just out of curiosity I added more fingerprints. And guess what? NO LAG! It's definitely something weird happening, but if it would be a hardware issue I would get a lag that I had before, but it's non existent. So this remedy below and reduce motion on=no lag for me.
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REMEDY!!! (hopefully this works) It worked for me, so far can't see any lag whatsoever
1. Erase all of your fingerprints
2. Register only ONE
3. Hard reset the phone
*My theory on this is that something is wrong with the touch id, because when i turned it off I could not replicate any lag anymore. Signing with password everything worked smooth. So I thought, is there a possibility than this updated touch id comparing data of different fingerprints and since its so fast it unlocks it prior to stop "processing" information on the touch id. Therefore having only one finger in the database solved it because no process happening. I might be totally wrong on this "theory". But it works. Left phone for 10-15-20 minute and after waking it up everything is fast and smooth.
PLEASE try it and see if that helps.