atum3d printer help - unable to make tall parts

• I currently am working on getting an atum3d printer to work and obviously have some issues. For some reason, I am able to make some smaller prints (in z direction) successfully, but when it comes to printing pieces that push closer to the limit in the z direction, I am not able to. Pretty early on into the print (but not the first couple layers), the build plate fails to peel off after a layer, or maybe does not connect to start a new layer? So the build plate keeps going higher and higher but nothing is actually being made. I am calibrated btw. The variables that can be changed in the software include (my current settings in parenthesis)
• Default Layers: layer thickness (50 microns), rehab time (0), curing time (7 sec), retraction height (10 mm), retraction speed up (75 mm/min), time at top (0.5 sec), retraction speed down (75 mm/min).
• Initial Layers (1st four layers): Everything is the same but cure time is 60 seconds. It is important to make sure it sticks to the plate right?
• I am very frustrated that I can build small prints but not tall ones, but I am open to anything and everything. Thank you for your help, I really appreciate it.