First layer shift of a single color

Hi there,

I’m facing a weird issue, either caused by the software, the printer or maybe the model I made. I don’t know yet.

I made a name plate, that I print in PLA, 3 colors, face down. And for a weird reason, the first layer of the letters in blue, is shifted ~2mm to the left. I let the first print complete even after noticiyng the issue. Then I tried to re-slice, change the orientation, some parameters, but each time, the blue first layer is shifted.

Printer : P1S, peo textured plate, PolyTerra PLA (220°/55°)