It is quite possible that this layer is not lost, but due to mechanical problems in the Z direction, there is an uneven problem when moving from the upper layer to the next layer.
1. Increase the floor height. This problem may occur if the middle-level height setting is too low in the slicing software. You can set the layer height to 0.15 for the printing test.
2. Ensure smooth operation in the Z direction, apply lubricated silicone grease on the optical shaft and screw, and detect whether the directional bearing is damaged.
3. Check whether the Filament runs smoothly on the tray rack.