It is recommended to adjust the screws at the marked positions first. If there is no improvement, check the gear or replace the nozzle with a new one.
If the problem is still not solved, please reproduce the abnormal situation and take a video for us to analyze.
Neptune 4 Plus/max- How to replace nozzle:
https://drive.google.com/file/d/1Mq6meY0yKatWUWKyBqaOS6CBevSW1IS0/view?usp=sharing
Gear Assembly Removal Instructions:
https://drive.google.com/file/d/1i2DuK0ceWGDeNG1z54GCyNYg0eAUIS1S/view?usp=share_link