First Layer issue, but just in two spots

Lately, when i print anything, and on any plate, there are two spots that are printed like you can see in the picture. Always the same two spots. Any plate. Any filament.

I did check the screws > fine

I did try several filaments, no difference.

I did a full calibration, no difference.

Any idea? 97% of the rest of the first layer is perfect.