I can't print on the whole surface of the bed 125x125 / Je ne peux pas imprimer sur toute la surface du lit 125x125

Manu is having an issue with the 2.6 firmware.

What firmware are you running? You can find it from the touch screen, Settings, About.

Manu also pointed out that you should be able to see the problem in the Calibration menu, without needing to do the partial print that I suggested.