Under the influence of cold air, the top layer of extruded filaments will shrink, while the bottom layer of filaments continuously heated by the heated bed will expand, and its edge will easily tilt up or even break away from the glass plate. It will cause the bottom of the print to be deformed, or even fail to print.
The first layer does not stick to the glass plate.
The printing parameters are improper.
The ambient temperature is too low.
See First Layer Does Not Stick.
Refer to the information provided by the filament manufacturer to set the correct printing parameters, including:
a) Heated bed temperature;
b) Some models need to set single-layer adhesion or multi-layer adhesion when printing;
c) Some models require that the model cooling fan cannot be turned on during printing.