Ink does not adhere to paper (Xerox Phaser 600)

I posted here the other time, and I was able to solve my problem, thank you very much! Now, I have another problem lmao, it turns out that the ink does not adhere to the paper, not completely because at the end of the sheet the print is fine, but the problem is in the middle and at the beginning (and not always, only sometimes) It also has colored lines and black lines.. Does anyone know what needs to be maintained? The toners are not original btw