I am a learner. Got a new P1P printer some months ago. Loved it and all went well.
Being new to the hobby I used just PLA and PETG. Printed several items.
Recently tried to print a simple rectangular box about 90x160mm using PETG.
When just a few layers of the solid base were laid down, two of the diagonally opposite corners started to curl up off the base (aka warp??).
Research said it was an adherence problem with various possible causes.
I carefully cleaned the plate with soapy water.
I retried the model with a wide brim and the same problem happened.
The PETG reel (Creality) is new so I don’t think it’s a dampness filament problem.
Being a beginner I took all the defaults in Bambu Lab for Generic PETG (none available for Creality). Creality says 230-250 degrees. Bambu Lab sets it to 255. I assume slightly too high won’t cause ‘warping’. There are so many parameters related to temperature and cooling that I am reluctant to start changing them without knowing the reason.
The model is downloaded from MakerWorld without any changes.
Cable Organizing Boxes - Free 3D Print Model - MakerWorld
Any advice to diagnose would be much appreciated.
PETG hates the cold. Your P1P printer is not enclosed. Try a (much) warmer ambient environment, or get the cardboard box the printer came in and drop it over the printer, turn on the build plate heater (you do have it turned on already for PETG, right?) and wait 5-10 minutes before you start the job.
Thank you for your interest. The default plate is textured PEI and the default temps (initial and other) are both 80 degrees C. The room (small) is centrally heated and has an ambient of about 18 degrees C. Why wait the 10 minutes? The plate will already be up to temperature? On both attempts the base part was badly warped so I assumed minor tweaks with temperature were unlikely to help. Please, how should I proceed?
Wait 10 minutes for the build plate heater to warm up the air inside the box.
The air temperature has to be a lot hotter than 18º before it isn’t cold enough to make a difference. 18ºC is actually kind of cold for 3D printing, so this is almost certainly the problem.
PLA is a very popular filament because it’s easy to print. It doesn’t warp that much. The higher temperature filaments like PETG, Nylon and ABS are more prone to warping in part because the temperature change from extruded to cooled off is greater, and the plastic changes size (shrinks) as it cools. These plastics can also have higher coefficients of thermal expansion, meaning the change dimension more per degree of temperature change than PLA, which also makes the more prone to warping. ABS has the highest thermal expansion, I think, which is why no one likes to print with ABS. 
My current print right now: Room temperature 26°C, chamber temperature 46°C
Also slow down print speed quite a bit, but the result is very good layer to layer adhesion
Thank you both for those comments. When I bought the P1P I did consider the P1S as an alternative. Then I wondered why I could possibly want an enclosure. Now I know. I had never considered that ambient room temperature could impact the operation of a 3D printer. I will first try to print the box using PLA. That’s simpler than trying to control the ambient temperature. Maybe when the Summer comes I’ll try again with PETG !!!