Toner does not stop on the paper

Initially, I was convinced by the price (70 euros) and the toner.
Unfortunately, the disillusionment came relatively quickly as the prints were demanding and not just on white 80g paper with text.

Is allowed on thicker paper or on paper which design for laser printers does not hold the toner and can be blurred or the pressure is equal smeared from the printer after printing.

In the original toner cartridges I had not these problems and all prints were always perfect.

The problem now is that my prints still have black lines with it and probably the drum unit must be replaced now the savings effect is now gone because the part is not exactly cheap.

My conclusion for the future: Saving is OK but who wants to take pleasure in its print and here a little more emphasis on quality sets should stay with the original.