Bottom of Elegoo Rook has horizontal lines

[Zombies.aaargh]

I'm using an Elegoo Saturn.It's absolutely brand new out of the box, all default settings, no customizations, changes or modifications. Elegoo brand resin.I followed the setup instructions to the letter and printed out the Rook using the default settings, but they came out like this (See picture).The tops are perfect but the bottom has these horizontal lines. The damage at the bottom is my fault as they absolutely would not come off the build plate so I had to really hack at them.Does this look like a problem with my printer, my settings, or is is likely because it's a brand new printer and the lifting mechanism is a bit still.This is my first resin printer so I may have made a mistake during setup.