Hello together.

I got my Ender3 last week. Only did some extrusion calibration so far.
My biggest problem for now: It feels like the glas bed I bought with it is not flat. If I level it with the "paper tactic" to like a little bit of resistance in the corners (right there where the adjustment screws are) there?s really much space in the middle of the bed. When I adjust it that the nozzle literaly touches the bed in the corners, i can get 2 sheet of paper between the nozzle and the bed in the middle.

I really dont know what i do wrong...
Cant imagine that the glass isnt flat.

Any idea?

- Alex