Unknown problem

Hey Guys i printet some Walls with my Snapmaker 2.0 A350. I dont know why, but in the Center of my bed. this structure appears. It‘s Not the First time.
Please help

Is this from a publicly available fileset? By the looks of it I would GUESS that your infill is too low, or you don’t have enough top thickness, but those are just WAGs (wild-a**-guesses)

If the files are available I can pull them in and look at them.

That is the result of the bed, or the nozzle, being too hot. Try dropping the temperature of the bed by 5°C, 10°C, and 15°C. If that doesn’t work, try dropping the temperature of the nozzle by 5°C, 10°C, 15°C, and 20°C. Only make one change per try, then try combinations.

Share the gcode with us to get more information.
I think you are too near to the center of the bed but i can’t see the thickness of your objects.