It is normal for FDM type printers to have certain layer textures during the printing process. To improve print quality, we recommend trying:
1. Check the screws at the marked locations; these need to remain loose.
2. Check the video to see if the X-axis and the heated bed are parallel.
https://www.youtube.com/watch?v=SNqO084jRME
3.Check whether the extruder and heating bed are shaking;If it shakes, you can adjust the screw at the marked position. Each turn is about 1/6 turn, and may need to be adjusted multiple times.
https://www.youtube.com/watch?v=7WKe6dqZfMQ&t=356s （04:15) *The adjustment steps are the same for neptune 3 and Neptune 4 series printers.
https://www.youtube.com/watch?v=sZwFBdHdo4k （03:29）
4. Check the X/Y belt; please try to tighten the belt, turn 1/6 test counterclockwise each time.
5.Check whether the diameter of the filament you are using is stable; usually the error should not exceed ±0.02mm, and moisture in the filament will also cause a decrease in print quality.
After confirming the above, please find "input shaper" in the settings menu and calibrate the X/Y axis.When calibrating, make sure the print is placed on a flat table and that the base of the printer does not shake.
Also,It is recommended to use the default settings of elegoo cura；Neptune 4 series printers have faster printing speeds, and Rapid PLA is more recommended.
https://www.elegoo.com/pages/download
Cooperating to troubleshoot the problem will not affect the warranty.