I bought my Sl1s Resin printer 2 years ago and went through a dozen failed prints before I abandoned it and decided Resin printing wasn't for me. Fast forward I had a printing project I needed resin for, so I resolved to go through it one more time.  I found a post in here saying during calibration to apply downward pressure on the plate while tightening the screw.

Holy smokes it worked!  Retroactively I now know the tiny written instructions on the LED say to do this while calibrating.  I looked at the pictures but had never paid attention to the text.  RTFM!  I have been printing FDM for many years and considered myself a savy 3D print guy.  This was pretty embarassing.  Whoever posted that reminder, THANK YOU!  I was literally about to sell my printer and never look back.