Possible solutions
Improper calibration
Step 1) start by recalibrating the build plate to the print surface. Loosen both X,Y knob and Z knob on the build plate. Select the prepare button in the prepare tab, the build plate will lower. Once the build plate reaches the bottom of the print surface secure firmly downward to make even with the print surface of the petri dish. Once flat tighten the XY,& Z screw on the build plate arm and select continue to move forward in the print process.
Improper print parameters
Step 2) Be sure to check all the protocols for the photo resin you are printing within your application. Be sure that you have selected the proper power output for the projector, the correct amount of exposure time, and that your print bed is heating properly. Try increasing the first layer exposure time to get better adhesion for your print to the build surface.